Composite optical articles

ABSTRACT

Provided is a composite optical article including (a) a polymeric base layer comprising a sulfur-containing urethane-based material having a refractive index of at least 1.57; and (b) a polymeric outer layer cast over a surface of the base layer (a) comprising (i) a poly(urea-urethane) material having a refractive index of less than 1.57, and (ii) a photochromic compound and/or a static dye. The thickness of the base layer (a) is greater than the thickness of the outer layer (b).

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority of U.S. ProvisionalPatent Application No. 61/449,339, filed Mar. 4, 2011 which isincorporated by reference herein.

FIELD OF THE INVENTION

The present invention relates to composite optical articles comprising apolymeric base layer of sulfur-containing urethane-based material havinga refractive index of 1.57 or greater, and a polymeric outer layer castover the base layer which has a refractive index of less than 1.57 whichcontains photochromic dyes and/or static tints. The optical articles ofthe invention are particularly suitable as light weight sun lenses.

BACKGROUND OF THE INVENTION

Optical elements that provide acceptable optical qualities whilemaintaining durability and abrasion resistance are sought for a varietyof applications, such as windshields, sunglasses, fashion lenses,non-prescription and prescription lenses, sport masks, face shields andgoggles. Responsive to that need, optical elements prepared from avariety of durable organic polymers have been developed.

A number of organic polymeric materials, such as plastics, have beendeveloped as alternatives and replacements for glass in applicationssuch as optical lenses, fiber optics, windows and automotive, nauticaland aviation transparencies. These polymeric materials can provideadvantages relative to glass including shatter resistance, lighterweight for a given application, ease of molding and ease of dyeing.However, the refractive indices of many polymeric materials are lowerthan that of glass. In ophthalmic applications, the use of a polymericmaterial having a lower refractive index will require a thicker lens,which is generally undesirable, relative to a material having a higherrefractive index and lower weight and density.

Poly (urea-urethane) materials are known in the art to provide opticalarticles having light weight, excellent impact resistance and strength.However, the refractive index of such materials typically is lower thanthat of glass. Sulfur-containing lens materials such as thiourethanesare known to have higher refractive index, but lack the strengthprovided by the poly(urea-urethane) materials. Moreover, it is difficultto incorporate organic photochromic materials and static dyes intoarticles formed from sulfur-containing lens materials because the sulfurcompounds can have a negative impact on fatigue resistance of thephotochromic materials, and can pause color shifts of both thephotochromic and static dyes.

The composite optical article of the present invention overcomes theaforementioned problems.

SUMMARY OF THE INVENTION

The present invention relates to a composite optical article comprising:

-   -   (a) a polymeric base layer comprising a sulfur-containing        urethane-based material having a refractive index of at least        1.57; and    -   (b) a polymeric outer layer cast over a surface of the base        layer (a) comprising:        -   (i) a poly(urea-urethane) material having a refractive index            of less than 1.57, and        -   (ii) a photochromic compound and/or a static dye. The            thickness of the base layer (a) is greater than the            thickness of the outer layer (b).

DETAILED DESCRIPTION OF THE INVENTION

It is noted that, as used in this specification and the appended claims,the singular forms “a,” “an,” and “the” include plural referents unlessexpressly and unequivocally limited to one referent.

For the purposes of this specification, unless otherwise indicated, allnumbers expressing quantities of ingredients, reaction conditions, andother parameters used in the specification and claims are to beunderstood as being modified in all instances by the term “about.”Accordingly, unless indicated to the contrary, the numerical parametersset forth in the following specification and attached claims areapproximations that may vary depending upon the desired properties to beobtained by the present invention. At the very least, and not as anattempt to limit the application of the doctrine of equivalents to thescope of the claims, each numerical parameter should at least beconstrued in light of the number of reported significant digits and byapplying ordinary rounding techniques.

All numerical ranges herein include all numerical values and ranges ofall numerical values within the recited numerical ranges.Notwithstanding that the numerical ranges and parameters setting forththe broad scope of the invention are approximations, the numericalvalues set forth in the specific examples are reported as precisely aspossible. Any numerical value, however, inherently contain certainerrors necessarily resulting from the standard deviation found in theirrespective testing measurements.

The various embodiments and examples of the present invention aspresented herein are each understood to be non-limiting with respect tothe scope of the invention.

As used in the following description and claims, the following termshave the meanings indicated below:

The terms “acrylic” and “acrylate” are used interchangeably (unless todo so would alter the intended meaning) and include acrylic acids,anhydrides, and derivatives thereof, such as their C₁-C₅ alkyl esters,lower alkyl-substituted acrylic acids, e.g., C₁-C₅ substituted acrylicacids, such as methacrylic acid, ethacrylic acid, etc., and their C₁-C₅alkyl esters, unless clearly indicated otherwise. The terms“(meth)acrylic” or “(meth)acrylate” are intended to encompass both theacrylic/acrylate and methacrylic/methacrylate forms of the indicatedmaterial, e.g., a (meth)acrylate monomer.

The terms “oligomer” and “oligomeric” are intended to refer to compoundsprepared by addition polymerization to yield a material having repeatingunits and having a number average molecular weight up to 5000, or up to2000, or between 200 and 1200. The number average molecular weight maybe determined by gel permeation chromatography using a polystyrenestandard.

The term “curable”, as used for example in connection with a curablecomposition, means that the indicated composition is polymerizable orcross-linkable through functional groups, e.g., by means that include,but are not limited to, thermal, catalytic, electron beam, chemicalfree-radical initiation, and/or photo-initiation such as by exposure toultraviolet light or other actinic radiation.

The term “cure”, “cured” or similar terms, as used in connection with acured or curable composition, e.g., a “cured composition” of somespecific description, means that at least a portion of the polymerizableand/or crosslinkable components that form the curable composition ispolymerized and/or crosslinked. Additionally, curing of a polymerizablecomposition refers to subjecting said composition to curing conditionssuch as but not limited to thermal curing, leading to the reaction ofthe reactive functional groups of the composition, and resulting inpolymerization and formation of a polymerizate. When a polymerizablecomposition is subjected to curing conditions, following polymerizationand after reaction of most of the reactive end groups occurs, the rateof reaction of the remaining unreacted reactive end groups becomesprogressively slower. The polymerizable composition can be subjected tocuring conditions until it is at least partially cured. The term “atleast partially cured” means subjecting the polymerizable composition tocuring conditions, wherein reaction of at least a portion of thereactive groups of the composition occurs, to form a polymerizate, suchthat said polymerizate can be demolded, and cut into test pieces, orsuch that it may be subjected to machining operations, including opticallens processing. The polymerizable composition can also be subjected tocuring conditions such that a substantially complete cure is attainedand wherein further curing results in no significant further improvementin polymer properties, such as hardness.

The term “reactive compound” refers to a compound capable of undergoinga chemical reaction with itself and/or other compounds spontaneously orupon the application of heat, actinic radiation, or in the presence of acatalyst or by any other means known to those skilled in the art.

The terms “on”, “appended to”, “affixed to”, “bonded to”, “adhered to”,or terms of like import mean that the designated item, e.g., a coating,film or layer, is either directly connected to (e.g., superimposed on)the object surface, or indirectly connected to the object surface, e.g.,through one or more other coatings, films or layers (superposed on).

The term “ophthalmic” refers to elements and devices that are associatedwith the eye and vision, such as but not limited to, lenses for eyewear,e.g., corrective and non-corrective lenses, and magnifying lenses.

The term “optical quality”, as used for example in connection withpolymeric materials, e.g., a “resin of optical quality” or “organicpolymeric material of optical quality” means that the indicatedmaterial, e.g., a polymeric material, resin, or resin composition, is orforms a substrate, layer, film or coating that can be used as an opticalarticle, such as an ophthalmic lens, or in combination with an opticalarticle.

The term “rigid”, as used for example in connection with an opticalsubstrate or an optical article, means that the specified item isself-supporting; i.e., capable of maintaining its shape and supportingany applied coatings and/or films. The optical substrate itself may bein the form of a film or sheet. A rigid item may also be defined ascapable of being demolded and cut into test pieces, or subjected tomachining operations, without permanent deformation. Alternatively, arigid article may be described as having a Martens hardness of at least20 N/mm², as defined herein.

The term “optical article” means that the specified article exhibits avisible light transmittance value (transmits incident light) of at least4 percent, such as at least 50 percent, or at least 70 percent, or atleast 85 percent; and exhibits a haze value of less than 5 percent,e.g., less than 1 percent or less than 0.5 percent, when the haze valueis measured at 550 nanometers by, for example, a Haze Gard PlusInstrument. Optical articles can include, but are not limited to, fiberoptics, windows and automotive, nautical and aviation transparencies,lenses, optical layers, e.g., optical resin layers, optical films, suchas films and/or sheets suitable for electronic displays, e.g., monitors,screens, or security elements, optical coatings, and optical substrateshaving a light influencing property.

The term “photochromic receptive” means that the indicated item hassufficient free volume to permit photochromic material(s) incorporatedwithin it to transform from its colorless form to its colored form (andthen revert to its colorless form) to the degree required for commercialoptical applications.

The term “tinted”, as used for example in connection with ophthalmicelements and optical substrates, means that the indicated item containsa fixed light radiation absorbing agent, such as but not limited to,conventional coloring dyes and/or pigments, infrared and/or ultravioletlight absorbing materials on or in the indicated item. The tinted itemhas an absorption spectrum for visible radiation that does not varysignificantly in response to actinic radiation.

The term “non-tinted”, as used for example in connection with ophthalmicelements and optical substrates, means that that the indicated item issubstantially free of fixed light radiation absorbing agents. Thenon-tinted item has an absorption spectrum for visible radiation thatdoes not vary significantly in response to actinic radiation.

The term “radiation curable” refers to compositions that may be cured bymeans of ionizing radiation such as electron beam, actinic radiation,and the like.

The term “actinic radiation” includes light with wavelengths ofelectromagnetic radiation ranging from the ultraviolet (“UV”) lightrange, through the visible light range, and into the infrared range.Actinic radiation which can be used to cure coating compositions used inthe present invention generally has wavelengths of electromagneticradiation ranging from 150 to 2,000 nanometers (nm), from 180 to 1,000nm, or from 200 to 500 nm. In one embodiment, ultraviolet radiationhaving a wavelength ranging from 10 to 390 nm can be used. Examples ofsuitable ultraviolet light sources include xenon arc lamps, mercuryarcs, carbon arcs, low, medium or high pressure mercury lamps,swirl-flow plasma arcs and ultraviolet light emitting diodes. Suitableultraviolet light-emitting lamps are medium pressure mercury vapor lampshaving outputs ranging from 200 to 600 watts per inch (79 to 237 wattsper centimeter) across the length of the lamp tube.

The term “transparent”, as used for example in connection with asubstrate, film, material and/or coating, means that the indicatedsubstrate, coating, film and/or material has the property oftransmitting light without appreciable scattering so that objects lyingbeyond are entirely visible.

As mentioned above, the present invention provides a composite opticalarticle comprising: (a) a polymeric base layer comprising asulfur-containing urethane-based material having a refractive index ofat least 1.57, for example from 1.57 to 1.70; and (b) a polymeric outerlayer cast over a surface of the base layer (a) comprising (i) apoly(urea-urethane) material having a refractive index of less than1.57, for example from 1.50 to 1.55, and (ii) a photochromic compoundand/or a static dye as are described hereinbelow. The thickness of thebase layer (a) is greater than the thickness of the outer layer (b).Generally, the thickness of the outer layer (b) ranges from 0.3 to 1.0millimeter, such as from 0.5 to 1.0 millimeter. It should be mentionedthat the base layer (a) has a thickness sufficient to maintain opticalpower. That is, the base layer (a) can be the “power portion” of theoptical article.

Further, the base layer (a) is transparent (clear with no colorants ordyes included). That is, the base layer (a) can be substantially free ofphotochromic dyes, static dyes, or tints or any ingredients which wouldimpart color.

Polymeric Base Layer

The sulfur-containing material suitable for use as the polymeric baselayer (a) can include any of those known in the art. For example thebase layer (a) can comprise the reaction product of

(A) a reactive compound comprising a material having functional groupsthat are reactive with active hydrogens (e.g., polyisocyanates asdescribed herein below);

(B) a thioether-functional, oligomeric polythiol prepared by reactingtogether:

-   -   (1) a compound having at least two thiol functional groups;    -   (2) a compound having triple bond functionality; and optionally,    -   (3) a compound having at least two double bonds;

and, optionally,

(C) a compound different from (B) containing active hydrogens.

Such materials are described herein below in detail.

Particularly useful thioether-functional, oligomeric polythiols arethose having pendant hydroxyl groups. Such materials can included thosethioether-functional, oligomeric polythiols having pendant hydroxylfunctional groups which are prepared by reacting together:

(a) a compound having at least two thiol functional groups; and

(b) a hydroxyl functional compound having triple bond functionality.

The compound (a) having at least two thiol functional groups maycomprise a polythiol, i.e., a dithiol, a compound having more than twothiol functional groups (a higher polythiol), or a mixture thereof. Suchmixtures may include mixtures of dithiols, mixtures of higher polythiolsor mixtures of dithiols and higher polythiols. The thiol functionalgroups are typically terminal groups, though a minor portion (e.g., lessthan 50 percent of all groups) may be pendant along a chain. Thecompound (a) may additionally contain a minor portion of other activehydrogen functionality (i.e., different from thiol), for example,hydroxyl functionality. The compound (a) may be linear or branched, andmay contain cyclic, alkyl, aryl, aralkyl, or alkaryl groups.

The compound (a) can be selected so as to produce a substantially linearoligomeric polythiol. Therefore, when the compound (a) comprises amixture of a dithiol and a compound having more than two thiolfunctional groups, the compound having more than two thiol functionalgroups can be present in an amount up to 10 percent by weight of themixture.

Suitable dithiols can include linear or branched aliphatic,cycloaliphatic, aromatic, heterocyclic, polymeric, oligomeric dithiolsand mixtures thereof. The dithiol can comprise a variety of linkagesincluding but not limited to ether linkages (—O—), sulfide linkages(—S—), polysulfide linkages (—S_(x)—, wherein x is at least 2, or from 2to 4), ester linkages, amide linkages and combinations of such linkages.

Non-limiting examples of suitable dithiols for use in the presentinvention can include but are not limited to2,5-dimercaptomethyl-1,4-dithiane, dimercaptodiethylsulfide (DMDS),ethanedithiol, 3,6-dioxa-1,8-octanedithiol, ethylene glycoldi(2-mercaptoacetate), ethylene glycol di(3-mercaptopropionate),poly(ethylene glycol) di(2-mercaptoacetate) and poly(ethylene glycol)di(3-mercaptopropionate), benzenedithiol,4-tert-butyl-1,2-benzenedithiol, 4,4′-thiodibenzenethiol, and mixturesthereof.

The dithiol may include dithiol oligomers having disulfide linkages suchas materials represented by the following graphic formula I:

wherein n can represent an integer from 1 to 21.

Dithiol oligomers represented by Formula I can be prepared, for example,by the reaction of 2,5-dimeracaptomethyl-1,4-dithiane with sulfur in thepresence of basic catalyst, as known in the art.

The nature of the SH group in polythiols is such that oxidative couplingcan occur readily, leading to formation of disulfide linkages. Variousoxidizing agents can lead to such oxidative coupling. The oxygen in theair can in some cases lead to such oxidative coupling during storage ofthe polythiol. It is believed that a possible mechanism for theoxidative coupling of thiol groups involves the formation of thiylradicals, followed by coupling of said thiyl radicals, to form disulfidelinkage. It is further believed that formation of disulfide linkage canoccur under conditions that can lead to the formation of thiyl radical,including but not limited to reaction conditions involving free radicalinitiation. The polythiols suitable for use as compound (a) in thepreparation of the polythiols of the present invention can includespecies containing disulfide linkages formed during storage. Thepolythiols suitable for use as compound (a) in the preparation of any ofthe oligomeric polythiols of the present invention also can includespecies containing disulfide linkages formed during synthesis of thepolythiol.

In certain embodiments, the dithiol suitable for use in the presentinvention, can include at least one dithiol represented by the followinggraphic formulas:

The sulfide-containing dithiols comprising 1,3-dithiolane (e.g.,formulas II and III) or 1,3-dithiane (e.g., formulas IV and V) can beprepared by reacting asym-dichloroacetone with dimercaptan, and thenreacting the reaction product with dimercaptoalkylsulfide, dimercaptanor mixtures thereof, as described in U.S. Pat. No. 7,009,032 B2.

Non-limiting examples of suitable dimercaptans for use in the reactionwith asym-dichloroacetone can include but are not limited to materialsrepresented by the following formula VI:

wherein Y can represent CH₂ or (CH₂—S—CH₂), and n′ can be an integerfrom 0 to 5. The dimercaptan suitable for reaction withasym-dichloroacetone in the present invention can be chosen from, forexample, ethanedithiol, propanedithiol, and mixtures thereof.

The amount of asym-dichloroacetone and dimercaptan suitable for carryingout the above reaction can vary. For example, asym-dichloroacetone anddimercaptan can be present in the reaction mixture in an amount suchthat the molar ratio of dichloroacetone to dimercaptan can be from 1:1to 1:10.

Suitable temperatures for reacting asym-dichloroacetone with dimercaptancan vary, often ranging from 0 to 100° C.

Non-limiting examples of suitable dimercaptans for use in the reactionwith the reaction product of the asym-dichloroacetone and dimercaptan,can include but are not limited to materials represented by the abovegeneral formula VI, aromatic dimercaptans, cycloalkyl dimercaptans,heterocyclic dimercaptans, branched dimercaptans, and mixtures thereof.

Non-limiting examples of suitable dimercaptoalkylsulfides for use in thereaction with the reaction product of the asym-dichloroacetone anddimercaptan, can include but are not limited to materials represented bythe following formula:

wherein X can represent O, S or Se, n″ can be an integer from 0 to 10, mcan be an integer from 0 to 10, p can be an integer from 1 to 10, q canbe an integer from 0 to 3, and with the proviso that (m+n″) is aninteger from 1 to 20.

Non-limiting examples of suitable dimercaptoalkylsulfides for use in thepresent invention can include branched dimercaptoalkylsulfides.

The amount of dimercaptan, dimercaptoalkylsulfide, or mixtures thereof,suitable for reacting with the reaction product of asym-dichloroacetoneand dimercaptan, can vary. Typically, dimercaptan,dimercaptoalkylsulfide, or a mixture thereof, can be present in thereaction mixture in an amount such that the equivalent ratio of reactionproduct to dimercaptan, dimercaptoalkylsulfide, or a mixture thereof,can be from 1:1.01 to 1:2. Moreover, suitable temperatures for carryingout this reaction can vary within the range of from 0 to 100° C.

The reaction of asym-dichloroacetone with dimercaptan can be carried outin the presence of an acid catalyst. The acid catalyst can be selectedfrom a wide variety known in the art, such as but not limited to Lewisacids and Bronsted acids. Non-limiting examples of suitable acidcatalysts can include those described in Ullmann's Encyclopedia ofIndustrial Chemistry, 5^(th) Edition, 1992, Volume A21, pp. 673 to 674.The acid catalyst is often chosen from boron trifluoride etherate,hydrogen chloride, toluenesulfonic acid, and mixtures thereof. Theamount of acid catalyst can vary from 0.01 to 10 percent by weight ofthe reaction mixture.

The reaction product of asym-dichloroacetone and dimercaptan canalternatively be reacted with dimercaptoalkylsulfide, dimercaptan ormixtures thereof, in the presence of a base. The base can be selectedfrom a wide variety known in the art, such as but not limited to Lewisbases and Bronsted bases. Non-limiting examples of suitable bases caninclude those described in Ullmann's Encyclopedia of IndustrialChemistry, 5^(th) Edition, 1992, Volume A21, pp. 673 to 674. The base isoften sodium hydroxide. The amount of base can vary. Typically, asuitable equivalent ratio of base to reaction product of the firstreaction, can be from 1:1 to 10:1.

The reaction of asym-dichloroacetone with dimercaptan can be carried outin the presence of a solvent. The solvent can be selected from but isnot limited to organic solvents. Non-limiting examples of suitablesolvents can include but are not limited to chloroform, dichloromethane,1,2-dichloroethane, diethyl ether, benzene, toluene, acetic acid andmixtures thereof.

In another embodiment, the reaction product of asym-dichloroacetone anddimercaptan can be reacted with dimercaptoalkylsulfide, dimercaptan ormixtures thereof, in the presence of a solvent, wherein the solvent canbe selected from but is not limited to organic solvents. Non-limitingexamples of suitable organic solvents can include alcohols such as butnot limited to methanol, ethanol and propanol; aromatic hydrocarbonsolvents such as but not limited to benzene, toluene, xylene; ketonessuch as but not limited to methyl ethyl ketone; water; and mixturesthereof.

The amount of solvent can widely vary, from 0 to 99 percent by weight ofthe reaction mixtures. Alternatively, the reactions can be carried outneat, i.e., without solvent.

The reaction of asym-dichloroacetone with dimercaptan can also becarried out in the presence of a dehydrating reagent. The dehydratingreagent can be selected from a wide variety known in the art. Suitabledehydrating reagents for use in this reaction can include but are notlimited to magnesium sulfate. The amount of dehydrating reagent can varywidely according to the stoichiometry of the dehydrating reaction.

The compound (a) having at least two thiol functional groups, used toprepare the oligomeric polythiols of the present invention, can beprepared in certain non-limiting embodiments by reacting2-methyl-2-dichloromethyl-1,3-dithiolane with dimercaptodiethylsulfideto produce dimercapto-1,3-dithiolane derivative of formula III.Alternatively, 2-methyl-2-dichloromethyl-1,3-dithiolane can be reactedwith 1,2-ethanedithiol to produce dimercapto-1,3-dithiolane derivativeof formula II. 2-methyl-2-dichloromethyl-1,3-dithiane can be reactedwith dimercaptodiethylsulfide to produce dimercapto-1,3-dithianederivative of formula V. Also, 2-methyl-2-dichloromethyl-1,3-dithianecan be reacted with 1,2-ethanedithiol to produce dimercapto-1,3-dithianederivative of formula IV.

Another non-limiting example of a dithiol suitable for use as compound(a) in the preparation of the oligomeric polythiol of the presentinvention can include at least one dithiol oligomer prepared by reactingdichloro derivative with dimercaptoalkylsulfide as follows in ReactionScheme A:

wherein R can represent CH₃, CH₃CO, C₁ to C₁₀ alkyl, cycloalkyl, arylalkyl, or alkyl-CO; Y′ can represent C₁ to C₁₀ alkyl, cycloalkyl, C₆ toC₁₄ aryl, (CH₂)_(p′)(S)_(m′)(CH₂)_(q′), (CH₂)_(p′)(Se)_(m′)(CH₂)_(q′),(CH₂)_(p′)(Te)_(m′)(CH₂)_(q′) wherein m′ can be an integer from 1 to 5and, p′ and q′ can each be an integer from 1 to 10; n′″ can be aninteger from 1 to 20; and x can be an integer from 0 to 10.

The reaction of dichloro derivative with dimercaptoalkylsulfide can becarried out in the presence of a base. Suitable bases include any knownto those skilled in the art in addition to those disclosed above.

The reaction of dichloro derivative with dimercaptoalkylsulfide may becarried out in the presence of a phase transfer catalyst. Suitable phasetransfer catalysts for use in the present invention are known andvaried. Non-limiting examples can include but are not limited totetraalkylammonium salts and tetraalkylphosphonium salts. This reactionis often carried out in the presence of tetrabutylphosphonium bromide asphase transfer catalyst. The amount of phase transfer catalyst can varywidely, for example, from 0 to 50 equivalent percent, or from 0 to 10equivalent percent, or from 0 to 5 equivalent percent, relative to thedimercaptosulfide reactants.

The compound (a) having at least two thiol functional groups may furthercontain hydroxyl functionality. Non-limiting examples of suitablematerials having both hydroxyl and multiple (more than one) thiol groupscan include but are not limited to glycerin bis(2-mercaptoacetate),glycerin bis(3-mercaptopropionate), 1,3-dimercapto-2-propanol,2,3-dimercapto-1-propanol, trimethylolpropane bis(2-mercaptoacetate),trimethylolpropane bis(3-mercaptopropionate), pentaerythritolbis(2-mercaptoacetate), pentaerythritol tris(2-mercaptoacetate),pentaerythritol bis(3-mercaptopropionate), pentaerythritoltris(3-mercaptopropionate), and mixtures thereof.

In addition to dithiols disclosed above, particular examples of suitabledithiols for use as or in preparing the compound (a) can include1,2-ethanedithiol, 1,2-propanedithiol, 1,3-propanedithiol,1,3-butanedithiol, 1,4-butanedithiol, 2,3-butanedithiol,1,3-pentanedithiol, 1,5-pentanedithiol, 1,6-hexanedithiol,1,3-dimercapto-3-methylbutane, dipentenedimercaptan,ethylcyclohexyldithiol (ECHDT), dimercaptodiethylsulfide (DMDS),methyl-substituted dimercaptodiethylsulfide, dimethyl-substituteddimercaptodiethylsulfide, 3,6-dioxa-1,8-octanedithiol,1,5-dimercapto-3-oxapentane, 2,5-dimercaptomethyl-1,4-dithiane (DMMD),ethylene glycol di(2-mercaptoacetate), ethylene glycoldi(3-mercaptopropionate), and mixtures thereof.

Suitable trifunctional or higher-functional polythiols for use as or inthe preparation of compound (a) can be selected from a wide varietyknown in the art. Non-limiting examples can include pentaerythritoltetrakis(2-mercaptoacetate), pentaerythritoltetrakis(3-mercaptopropionate), trimethylolpropanetris(2-mercaptoacetate), trimethylolpropane tris(3-mercaptopropionate),and/or thioglycerol bis(2-mercaptoacetate).

For example, the polythiol can be chosen from materials represented bythe following formula VIII,

wherein R₁ and R₂ can each be independently chosen from straight orbranched chain alkylene, cyclic alkylene, phenylene and C₁-C₉ alkylsubstituted phenylene. Non-limiting examples of straight or branchedchain alkylene can include methylene, ethylene, 1,3-propylene,1,2-propylene, 1,4-butylene, 1,2-butylene, pentylene, hexylene,heptylene, octylene, nonylene, decylene, undecylene, octadecylene andicosylene. Non-limiting examples of cyclic alkylenes can includecyclopentylene, cyclohexylene, cycloheptylene, cyclooctylene, andalkyl-substituted derivatives thereof. The divalent linking groups R₁and R₂ can be chosen from methylene, ethylene, phenylene, andalkyl-substituted phenylene, such as methyl, ethyl, propyl, isopropyland nonyl substituted phenylene.

In particular embodiments, the compound (a) having at least two thiolfunctional groups may be prepared by reacting together (1) any of thedithiols mentioned above, and (2) a compound having at least two doublebonds (for example, a diene). Such compounds having at least two doublebonds are described in more detail below, as are reaction methods.

The compound (b) having triple bond functionality, used to prepare theoligomeric polythiols of the present invention, may comprise any alkyneknown to those skilled in the art. In the preparation of thethioether-functional oligomeric polythiols having pendant hydroxylfunctional groups, the compound (b) may comprise any hydroxyl functionalalkyne known in the art such as those described immediately below.Because a triple bond can react twice with a thiol functional group, forthe purposes of the present invention, a triple bond is understood to beequal to two equivalents of a double bond when determining reactionstoichiometry.

Suitable non-limiting examples of hydroxyl functional compounds havingtriple bond functionality include propargyl alcohol, 2-butyne-1,4-diol,3-butyne-2-ol, 3-hexyne-2,5-diol, and/or mixtures thereof. A portion ofthe hydroxyl functional groups on the compound (b) may be esterified.For example, a portion of the compound (b) may comprise analkyne-functional ester of a C₁-C₁₂ carboxylic acid such as propargylacetate, propargyl propionate, propargyl benzoate, and the like.Moreover, in the preparation of the thioether-functional, oligomericpolythiols having pendant hydroxyl groups, a portion of the triplebond-containing compound (b) can comprise, in addition to the hydroxylfunctional, triple bond-containing compound, a triple-bond-containingcompound which contains no hydroxyl functional groups such as thosedescribed hereinbelow.

In the preparation of the oligomeric polythiol of the present invention,the ratio of thiol functional groups in compound (a) to triple bonds incompound (b) typically ranges from 1.01:1 to 2.0:1, such as 1:3:1 to2.0:1, and 1.5:1 to 2.0:1. In some instances the presence of an excessof thiol functional groups may be desirable during the reaction as wellas in the reaction product as unreacted compound (a). For example, thepresence of excess thiol present during the reaction may enhance thereaction rate. Also unreacted thiol, e.g., in the form of unreactedcompound (a), can be present in the final reaction product and thusavailable to subsequently react with, for example, a reactive compoundhaving functional groups reactive with active hydrogens (such as aredescribed below). Thus, in an embodiment of the present invention thereaction ratio of thiol functional groups in the compound (a) to triplebonds in the compound (b) can range from 1.01:1 to 20:1, such as 1.01:1to 10:1, or 1.01:1 to 5:1, or 1.5:1 to 5:1; or 1.5:1 to 3:1.

To prepare the oligomeric polythiols of the present invention, thereaction of the compound (a) with triple bond-containing compounds (b)can be carried out in the presence of radical initiator. Suitableradical initiators for use in the present invention can vary widely andcan include those known to one of ordinary skill in the art.Non-limiting examples of radical initiators can include but are notlimited to azo or peroxide type free-radical initiators such asazobisalkalenenitriles. The free-radical initiator can beazobisalkalenenitrile which is commercially available from DuPont underthe trade name VAZO™. VAZO-52, VAZO-64, VAZO-67, VAZO-88 and mixturesthereof can also be used as radical initiators.

Selection of the free-radical initiator can depend on reactiontemperature. The reaction temperature can vary, for example, from roomtemperature to 120° C. VAZO 52 can be used at a temperature of from50-60° C. VAZO 64 and VAZO 67 can be used at a temperature of 60-100°C., and VAZO 88 can be used at a temperature of 70-120° C.

The amount of free radical initiator used in the reaction of the presentinvention can vary widely and can depend on the free radical initiatorselected. Typically, the free radical initiator is present in an amountof from 0.01% by weight to 5% by weight of the reaction mixture.

The reaction of the compound (a) with triple bond-containing compounds(b) can be carried out under a variety of reaction conditions. Suchconditions can depend on the degree of reactivity of the triple bondcontaining compound and the desired structure of the resulting polythiololigomer. In one reaction scheme, the reactants and a radical initiatorcan be combined together while heating the mixture. Alternatively,triple bond containing-compounds can be added in relatively smallamounts over a period of time to a mixture of polythiol and radicalinitiator at a certain temperature. Also, triple bondcontaining-compounds can be combined with the compound (a) having atleast two thiol functional groups in a stepwise manner under radicalinitiation. Also, the radical initiator can be dissolved in the triplebond-containing compound (b), and the resulting solution can be addeddropwise to the compound (a).

The present invention also is directed to a composition, such as acoating composition, comprising any of the thioether functional,oligomeric polythiols as previously described. The composition canfurther comprise a reactive compound comprising a material havingfunctional groups that are reactive with active hydrogens, such as anyof such compounds described in detail hereinbelow.

The present invention also is directed to, a thioether-functional,oligomeric polythiol having pendant hydroxyl functional groups preparedby reacting together:

(a) a compound having at least two thiol functional groups such as anyof those described above;

(b) a compound having triple bond functionality such as any of thosedescribed above; and

(c) a compound having at least two double bonds.

The compound (a) having at least two thiol functional groups may be anyof the previously mentioned thioether-functional, oligomeric polythiols,including those described above, prepared in accordance with the presentinvention. In one embodiment of the present invention, the compound (a)comprises a reaction product of (1) any of the dithiols mentioned above,and (2) a compound having at least two double bonds, which may be thesame as or different from the compound (c). The compound (b) can be anyof the previously mentioned compounds having triple bond functionality,including the hydroxyl functional compounds having triple bondfunctionality.

The compound (c) having at least two double bonds can be chosen fromnon-cyclic dienes, including straight chain and/or branched aliphaticnon-cyclic dienes, non-aromatic ring-containing dienes, includingnon-aromatic ring-containing dienes wherein the double bonds can becontained within the ring or not contained within the ring or anycombination thereof, and wherein the non-aromatic ring-containing dienescan contain non-aromatic monocyclic groups or non-aromatic polycyclicgroups or combinations thereof; aromatic ring-containing dienes; orheterocyclic ring-containing dienes; or dienes containing anycombination of such non-cyclic and/or cyclic groups. The dienes canoptionally contain thioether, disulfide, polysulfide, sulfone, ester,thioester, carbonate, thiocarbonate, urethane, or thiourethane linkages,or halogen substituents, or combinations thereof; with the proviso thatthe dienes contain at least some double bonds capable of undergoingreaction with SH groups of a polythiol, and forming covalent C—S bonds.Often the compound (c) having at least two double bonds comprises amixture of dienes that are different from one another.

The compound (c) having at least two double bonds may comprise acyclicnon-conjugated dienes, acyclic polyvinyl ethers, allyl-(meth)acrylatesvinyl-(meth)acrylates, di(meth)acrylate esters of diols,di(meth)acrylate esters of dithiols, di(meth)acrylate esters ofpoly(alkyleneglycol) diols, monocyclic non-aromatic dienes, polycyclicnon-aromatic dienes, aromatic ring-containing dienes, diallyl esters ofaromatic ring dicarboxylic acids, divinyl esters of aromatic ringdicarboxylic acids, and/or mixtures thereof.

Non-limiting examples of acyclic non-conjugated dienes can include thoserepresented by the following formula IX:

wherein R₃ can represent C₁ to C₃₀ linear or branched divalent saturatedalkylene radical, or C₂ to C₃₀ divalent organic radical including groupssuch as but not limited to those containing ether, thioether, ester,thioester, ketone, polysulfide, sulfone and combinations thereof. Theacyclic non-conjugated dienes can be selected from 1,5-hexadiene,1,6-heptadiene, 1,7-octadiene and mixtures thereof.

Non-limiting examples of suitable acyclic polyvinyl ethers can includethose represented by the following formula X:

CH₂═CH—O—(—R₄—O—)_(m″)—CH═CH₂  (X)

wherein R₄ can be C₂ to C₆ n-alkylene, C₃ to C₆ branched alkylene group,or —[(CH₂—)_(p″)—O—]_(q″)—(—CH₂—)_(r′)—, m″ can be a rational numberfrom 0 to 10, often 2; p″ can be an integer from 2 to 6, q″ can be aninteger from 1 to 5 and r′ can be an integer from 2 to 10.

Non-limiting examples of suitable polyvinyl ether monomers for use caninclude divinyl ether monomers, such as ethylene glycol divinyl ether,diethylene glycol divinyl ether, triethyleneglycol divinyl ether, andmixtures thereof.

Di(meth)acrylate esters of linear diols can include ethanedioldi(meth)acrylate, 1,3-propanediol dimethacrylate, 1,2-propanedioldi(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,3-butanedioldi(meth)acrylate, 1,2-butanediol di(meth)acrylate, and mixtures thereof.

Di(meth)acrylate esters of dithiols can include, for example,di(meth)acrylate of 1,2-ethanedithiol including oligomers thereof,di(meth)acrylate of dimercaptodiethyl sulfide (i.e.,2,2′-thioethanedithiol di(meth)acrylate) including oligomers thereof,di(meth)acrylate of 3,6-dioxa-1,8-octanedithiol including oligomersthereof, di(meth)acrylate of 2-mercaptoethyl ether including oligomersthereof, di(meth)acrylate of 4,4′-thiodibenzenethiol, and mixturesthereof.

Further non-limiting examples of suitable dienes can include monocyclicaliphatic dienes such as those represented by the following graphicformula XI:

wherein X′ and Y″ each independently can represent C₁₋₁₀ divalentsaturated alkylene radical; or C₁₋₅ divalent saturated alkylene radical,containing at least one element selected from the group of sulfur,oxygen and silicon in addition to the carbon and hydrogen atoms; and R₅can represent H, or C₁-C₁₀ alkyl; and those represented by the followinggraphic formula XII:

wherein X′ and R₅ can be as defined above and R₆ can represent C₂-C₁₀alkenyl. The monocyclic aliphatic dienes can include 1,4-cyclohexadiene,4-vinyl-1-cyclohexene, dipentene and terpinene.

Non-limiting examples of polycyclic aliphatic dienes can include5-vinyl-2-norbornene; 2,5-norbornadiene; dicyclopentadiene and mixturesthereof.

Non-limiting examples of aromatic ring-containing dienes can includethose represented by the following graphic formula XIII:

wherein R₄ can represent hydrogen or methyl. Aromatic ring-containingdienes can include monomers such as diisopropenyl benzene, divinylbenzene and mixtures thereof.

Examples of diallyl esters of aromatic ring dicarboxylic acids caninclude but are not limited to those represented by the followinggraphic formula XIV:

wherein each m′″ independently can be an integer from 0 to 5. Thediallyl esters of aromatic ring dicarboxylic acids can include o-diallylphthalate, m-diallyl phthalate, p-diallyl phthalate and mixturesthereof.

Often, the compound (c) having at least two double bonds comprises5-vinyl-2-norbornene, ethylene glycol divinyl ether, diethylene glycoldivinyl ether, triethylene glycol divinyl ether, butane diol divinylether, vinylcyclohexene, 4-vinyl-1-cyclohexene, dipentene, terpinene,dicyclopentadiene, cyclododecadiene, cyclooctadiene,2-cyclopenten-1-yl-ether, 2,5-norbornadiene, divinylbenzene including1,3-divinylbenzene, 1,2-divinylbenzene, and 1,4-divinylbenzene,diisopropenylbenzene including 1,3-diisopropenylbenzene,1,2-diisopropenylbenzene, and 1,4-diisopropenylbenzene,allyl(meth)acrylate, ethanediol di(meth)acrylate, 1,3-propanedioldi(meth)acrylate, 1,2-propanediol di(meth)acrylate, 1,3-butanedioldi(meth)acrylate, 1,2-butanediol di(meth)acrylate, ethylene glycoldi(meth)acrylate, diethylene glycol di(meth)acrylate,dimercaptodiethylsulfide di(meth)acrylate, 1,2-ethanedithioldi(meth)acrylate, and/or mixtures thereof.

Other non-limiting examples of suitable di(meth)acrylate monomers caninclude ethylene glycol di(meth)acrylate, 1,3-butylene glycoldi(meth)acrylate, 1,4-butanediol di(meth)acrylate,2,3-dimethyl-1,3-propanediol di(meth)acrylate, 1,6-hexanedioldi(meth)acrylate, propylene glycol di(meth)acrylate, dipropylene glycoldi(meth)acrylate, tripropylene glycol di(meth)acrylate, tetrapropyleneglycol di(meth)acrylate, ethoxylated hexanediol di(meth)acrylate,propoxylated hexanediol di(meth)acrylate, neopentyl glycoldi(meth)acrylate, alkoxylated neopentyl glycol di(meth)acrylate,hexylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate,polyethylene glycol di(meth)acrylate, thiodiethyleneglycoldi(meth)acrylate, trimethylene glycol di(meth)acrylate, triethyleneglycol di(meth)acrylate, alkoxylated hexanediol di(meth)acrylate,alkoxylated neopentyl glycol di(meth)acrylate, pentanedioldi(meth)acrylate, cyclohexane dimethanol di(meth)acrylate, andethoxylated bis-phenol A di(meth)acrylate.

For purposes of the present invention in the preparation of any of theoligomeric polythiols comprising reactants (a), (b), and (c), thereactants (a), (b), and (c) may all be reacted together simultaneously(as in a “one pot” process) or mixed together incrementally in variouscombinations. For example, compound (a) having at least two thiolfunctional groups may be reacted first with the compound (b) havingtriple bond functionality in a first reaction vessel to produce a firstreaction product, followed by addition of the compound (c) having atleast two double bonds to the reaction mixture to react with the firstreaction product and yield the oligomeric polythiol of the presentinvention (or addition of the first reaction product to a secondreaction vessel containing the compound (c)). As an alternative, thecompound (a) may be reacted first with the compound (c) having at leasttwo double bonds to produce a first reaction product, followed byaddition of the compound (b) to yield the oligomeric polythiol. In thisembodiment, one may optionally add, simultaneously with or aftercompound (b), an additional compound (c) having at least two doublebonds, which may be the same as or different from that reacted earlierwith compound (a) to form the first reaction product.

When the compound (a) is combined first with the compound (c), it isbelieved that they react via a thiol-ene type reaction of the SH groupsof (a) with double bond groups of (c). Such reactions may typically takeplace in the presence of a radical initiator as mentioned above, or inthe presence of a base catalyst, particularly when the compound (c)comprises a compound having at least one (meth)acrylate type doublebonds. Suitable base catalysts for use in this reaction can vary widelyand can be selected from those known in the art. Non-limiting examplescan include tertiary amine bases such as1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and N,N-dimethylbenzylamine.The amount of base catalyst used can vary widely, but typically it ispresent in an amount of from 0.001 to 5.0% by weight of the mixture of(a) and (c).

The stoichiometric ratio of the sum of the number of thiol equivalentsof all polythiols present (compound (a)) to the sum of the number ofequivalents of all double bonds present (including alkyne functionalityeffective as two double bond equivalents as discussed above) is greaterthan 1:1. In non-limiting embodiments, said ratio can be within therange of from greater than 1:1 to 3:1, or from 1.01:1 to 3:1, or from1.01:1 to 2:1, or from 1.05:1 to 2:1, or from 1.1:1 to 1.5:1, or from1.25:1 to 1.5:1.

Various methods of reacting polyvinyl ether monomers and one or moredithiol materials are described in detail in U.S. Pat. No. 6,509,418B1,column 4, line 52 through column 8, line 25, which disclosure is hereinincorporated by reference. Various methods of reacting allyl sulfide anddimercaptodiethylsulfide are described in detail in WO 03/042270, page2, line 16 to page 10, line 7, which disclosure is incorporated hereinby reference. Various methods for reacting a dithiol and an aliphatic,ring-containing non-conjugated diene in the presence of free radicalinitiator are described in detail in WO/01/66623A1, from page 3, line 19to page 6, line 11, the disclosure of which is incorporated herein byreference.

In reacting the compounds (a) and (c), it may be advantageous to use oneor more free radical initiators. Non-limiting examples of suitable freeradical initiators can include azo compounds, such as those describedabove; organic peroxides such as but not limited to benzoyl peroxide andt-butyl peroxide; inorganic peroxides; and similar free-radicalgenerators.

Alternately, the reaction of compounds (a) and (c) can be effected byirradiation with ultraviolet light either with or without aphotoinitiating moiety.

The mixture of (a) and (c) can be reacted for a time period of from 1hour to 5 days and at a temperature of from 20° C. to 100° C. Often, themixture is heated until a predetermined theoretical value for SH contentis achieved.

The stoichiometric ratio of the sum of the number of equivalents oftriple bond functional groups in compound (b) to the sum of the numberof equivalents of double bonds in compound (c) is often within the rangeof from 0.01:0.99 to 1.00:0, or from 0.10:0.90 to 1.00:0, or from0.20:0.80 to 1.00:0.

The present invention also is directed to a composition, such as acoating composition, comprising any of the thioether functional,oligomeric polythiols described immediately above comprising compounds(a), (b) and (c). The composition can further comprise any of thecompounds having functional groups reactive with active hydrogens asdescribed in detail hereinbelow.

As previously mentioned, suitable thioether functional, oligomericpolythiols useful for the preparation of the base layer (a) are thosecomprising a reaction product of:

-   -   (A) a reactive compound comprising a material having functional        groups that are reactive with active hydrogens, such as any of        those described herein below;    -   (B) a thioether functional, oligomeric polythiol prepared by        reacting together:        -   (1) a compound having at least two thiol functional groups            such as any of those described previously;        -   (2) a compound having triple bond functionality such as any            of those described herein above and below and, optionally,        -   (3) a compound having at least two double bonds such as any            of those described previously; and,

optionally,

-   -   (C) a compound different from (B) containing active hydrogens        described herein below.

In this embodiment, the compound having triple bond functionality cancomprise any known alkyne, for example, propargyl alcohol, propargylchloride, propargyl bromide, propargyl acetate, propargyl propionate,propargyl benzoate, phenyl acetylene, phenyl propargyl sulfide,1,4-dichloro-2-butyne, 2-butyne-1,4-diol, 3-butyne-2-ol, 2-pentyne,1-hexyne, 2-hexyne, 3-hexyne, 3-hexyne-2,5-diol, and/or mixturesthereof.

The composition can be used to prepare any of the articles ofmanufacture described hereinbelow such as optical articles, includingfilms and sheets; articles of manufacture for non-optical applications,for example, solar panels, body armor, interior and exterior aircraftand automotive parts such as doors, fascia, and propellers, housings forhand-held electronic devices such as cellular phones, and windmillblades; and coating compositions used to form various coatings,adhesives and/or sealants. In a particular embodiment, the compositioncomprises a coating composition which can provide coatings havingexcellent properties including, inter alia, impact and chemicalresistance, flexibility, anti-microbial and fungicidal properties, aswell as anti-ballistic and flame retardancy characteristics.

Any of the thioether-functional, oligomeric polythiols described herein,when reacted with a reactive compound having functional groups that arereactive with active hydrogens, can produce a polymerizate having arefractive index of at least 1.50, or at least 1.52, or at least 1.55,or at least 1.60, or at least 1.65, or at least 1.67. Additionally, thethioether-functional, oligomeric polythiol of the present invention,when reacted with a reactive compound having functional groups that arereactive with active hydrogens, can produce a polymerizate having anAbbe number of at least 30, or at least 35, or at least 38, or at least39, or at least 40, or at least 44. The refractive index and Abbe numbercan be determined by methods known in the art such as American StandardTest Method (ASTM) Number D 542-00, using various known instruments. Therefractive index and Abbe number can also be measured in accordance withASTM D 542-00 with the following exceptions: (i) test one to twosamples/specimens instead of the minimum of three specimens specified inSection 7.3; and (ii) test the samples unconditioned instead ofconditioning the samples/specimens prior to testing as specified inSection 8.1. Further, an Atago model DR-M2 Multi-Wavelength Digital AbbeRefractometer can be used to measure the refractive index and Abbenumber of the samples/specimens.

Further, any of the thioether-functional, oligomeric polythiolsdescribed herein, when reacted with a reactive compound havingfunctional groups that are reactive with active hydrogens, can produce apolymerizate having a Martens hardness of at least 20 N/mm², or often atleast 50, or more often between 70 and 200. Such polymerizates aretypically not elastomeric; i.e., they are not substantially reversiblydeformable (e.g., stretchable) due to their rigidity and do nottypically exhibit properties characteristic of rubber and otherelastomeric polymers.

Such polymerizates as discussed above may be used to prepare articles ofmanufacture having similar properties as described above, such as films,coatings, and molded items such as optical articles, in accordance withthe present invention.

The present invention is further drawn to rigid articles, such as rigidoptical articles, comprising a reaction product of:

(A) a reactive compound comprising a material having functional groupsthat are reactive with active hydrogens;

(B) a thioether-functional, oligomeric polythiol having pendant hydroxylfunctional groups, as discussed above; and optionally

(C) a compound different from (B) containing active hydrogens.

Optical articles of the present invention include ophthalmic articlessuch as plano (without optical power) and vision correcting(prescription having power) lenses: (finished and semi-finished)including multifocal lenses (bifocal, trifocal, and progressive lenses);and ocular devices such as contact lenses and intraocular lenses, sunlenses, fashion lenses, sport masks, face shields and goggles. Theoptical article also may be chosen from glazings such as architecturalwindows and vehicular transparencies such as automobile or aircraftwindshields and side windows.

Process for Forming Base Layer

In the preparation of the reaction products used to prepare the baselayer (a) of the optical articles of the present invention, thereactants (A), (B), and (C) may all be reacted together simultaneously(“one pot”) or mixed together incrementally in various combinations(“one or two pot”). Alternatively, reactive compound (A) may be reactedfirst with the oligomeric polythiol (B) to produce a prepolymer such asa sulfur-containing isocyanate-functional polyurethane, followed by postreaction of the compound (C) containing active, hydrogens with theprepolymer to yield the reaction products of the present invention. Inanother alternative, reactive compound (A) may comprise anisocyanate-functional polyurethane prepolymer prepared by reacting apolyisocyanate with any of the thioether-functional, oligomericpolythiols disclosed herein (e.g., reaction products of a compoundhaving at least two thiol functional groups, a compound having triplebond functionality, and optionally a compound having at least two doublebonds) and optionally another active hydrogen-containing material. Inthis alternative, reactive compound (A) may be reacted with theoligomeric polythiol (B) and compound (C) containing active hydrogens inany combination or order. In embodiments wherein any of the reactantscomprises two or more different compounds, the different compounds maybe reacted as a mixture or added separately or even at differenttimes/stages of the reaction. For example, the reaction product can beprepared by combining polyisocyanate and/or polyisothiocyanate,polythiol oligomer, optionally a first active hydrogen-containingmaterial, and optionally a urethanation catalyst, to form asulfur-containing polyurethane prepolymer, and then adding a second,different active hydrogen-containing material and optionallyurethanation catalyst to the sulfur-containing polyurethane prepolymer,and polymerizing the resulting mixture.

Note that the polyurethane prepolymer may contain disulfide linkages dueto disulfide linkages contained in the polythiol and/or polythiololigomer used to prepare the polyurethane prepolymer.

Each of the reactants (A), (B) and (C) can be degassed (e.g. undervacuum) prior to mixing them and carrying out the polymerization. Thereactants can be mixed using a variety of methods and equipment, such asbut not limited to an impeller or extruder.

The reactive compound (A) comprising a material having functional groupsthat are reactive with active hydrogens may comprise, for example, apolyisocyanate, a blocked polyisocyanate, a polyisothiocyanate, apolyepoxide, a polyepisulfide, a polyacid, an anhydride, apolyanhydride, a polyethylenically unsaturated material such as apolyvinyl ether or poly(meth)acrylate, and/or mixtures of the above.

As used herein, the term “polyisocyanate” is intended to include blocked(or capped) polyisocyanates as well as unblocked polyisocyanates.Polyisocyanates and polyisothiocyanates useful in the reactive compound(A) are numerous and widely varied. Suitable polyisocyanates for use inthe present invention can include but are not limited to polymeric andC₂-C₂₀ linear, branched, cyclic and aromatic polyisocyanates. Suitablepolyisothiocyanates for use in the present invention can include but arenot limited to polymeric and C₂-C₂₀ linear, branched, cyclic andaromatic polyisothiocyanates.

Non-limiting examples of suitable polyisocyanates andpolyisothiocyanates can include polyisocyanates having at least twoisocyanate groups; polyisothiocyanates having at least twoisothiocyanate groups; mixtures thereof; and combinations thereof, suchas a material having isocyanate and isothiocyanate functionality.

Non-limiting examples of polyisocyanates can include aliphaticpolyisocyanates, cycloaliphatic polyisocyanates wherein one or more ofthe isocyanato groups are attached directly to the cycloaliphatic ring,cycloaliphatic polyisocyanates wherein one or more of the isocyanatogroups are not attached directly to the cycloaliphatic ring, aromaticpolyisocyanates wherein one or more of the isocyanato groups areattached directly to the aromatic ring, and aromatic polyisocyanateswherein one or more of the isocyanato groups are not attached directlyto the aromatic ring. When an aromatic polyisocyanate is used, generallycare should be taken to select a material that does not cause the finalreaction product to color (e.g., yellow).

Examples of suitable polyisocyanates can include but are not limited toDESMODUR N 3300 (hexamethylene diisocyanate trimer) and DESMODUR N 3400(60% hexamethylene diisocyanate dimer and 40% hexamethylene diisocyanatetrimer), which are commercially available from Bayer Corporation.

The polyisocyanate can include dicyclohexylmethane diisocyanate andisomeric mixtures thereof. As used herein and the claims, the term“isomeric mixtures” refers to a mixture of the cis-cis, trans-trans, andcis-trans isomers of the polyisocyanate. Non-limiting examples ofisomeric mixtures for use in the present invention can include thetrans-trans isomer of 4,4′-methylenebis(cyclohexyl isocyanate),hereinafter referred to as “PICM” (paraisocyanato cyclohexylmetharie),the cis-trans isomer of PICM, the cis-cis isomer of PICM, and mixturesthereof.

Additional aliphatic and cycloaliphatic diisocyanates that can be usedinclude 3-isocyanato-methyl-3,5,5-trimethyl cyclohexyl-isocyanate(“isophorone diisocyanate” or “IPDI”) which is commercially availablefrom Arco Chemical, meta-tetramethylxylylene diisocyanate(1,3-bis(1-isocyanato-1-methylethyl)-benzene) which is commerciallyavailable from Cytec Industries Inc. as TMXDI® (Meta) AliphaticIsocyanate, and m-xylylene diisocyanate (MXDI). Mixtures of any of theforegoing may also be used.

As used herein and the claims, the terms aliphatic and cycloaliphaticdiisocyanates refer to 6 to 100 carbon atoms linked in a straight chainor cyclized having two diisocyanate reactive end groups. The aliphaticand cycloaliphatic diisocyanates for use in the present invention caninclude TMXDI and compounds of the formula R—(NCO)₂ wherein R representsan aliphatic group or a cycloaliphatic group.

Further non-limiting examples of suitable polyisocyanates andpolyisothiocyanates can include aliphatic polyisocyanates andpolyisothiocyanates; ethylenically unsaturated polyisocyanates andpolyisothiocyanates; alicyclic polyisocyanates and polyisothiocyanates;aromatic polyisocyanates and polyisothiocyanates wherein the isocyanategroups are not bonded directly to the aromatic ring, e.g., m-xylylenediisocyanate; aromatic polyisocyanates and polyisothiocyanates whereinthe isocyanate groups are bonded directly to the aromatic ring, e.g.,benzene diisocyanate; aliphatic polyisocyanates and polyisothiocyanatescontaining sulfide linkages; aromatic polyisocyanates andpolyisothiocyanates containing sulfide or disulfide linkages; aromaticpolyisocyanates and polyisothiocyanates containing sulfone linkages;sulfonic ester-type polyisocyanates and polyisothiocyanates, e.g.,4-methyl-3-isocyanatobenzenesulfonyl-4′-isocyanato-phenol ester;aromatic sulfonic amide-type polyisocyanates and polyisothiocyanates;sulfur-containing heterocyclic polyisocyanates and polyisothiocyanates,e.g., thiophene-2,5-diisocyanate; halogenated, alkylated, alkoxylated,nitrated, carbodiimide modified, urea modified and biuret modifiedderivatives of polyisocyanates thereof; and dimerized and trimerizedproducts of polyisocyanates thereof.

In particular embodiments of the present invention, the polyisocyanatescan include toluene diisocyanate, 4,4′-diphenylmethane diisocyanate,meta-xylylene diisocyanate, hydrogenated meta-xylylene diisocyanate(1,3-isocyanato-methylcyclohexane), 3-isocyanato-methyl-3,5,5-trimethylcyclohexyl-isocyanate, hexamethylene diisocyanate,meta-tetramethylxylylene diisocyanate(1,3-bis(1-isocyanato-1-methylethyl)-benzene), and/or4,4′-methylenebis(cyclohexyl isocyanate).

In certain embodiments the reactive compound (A) comprises adiisocyanate or a mixture of a diisocyanate and a polyisocyanate havingmore than two isocyanate functional groups. In such a case, thepolyisocyanate is present in an amount up to 10 percent by weight of themixture. In one embodiment, the reactive compound (A) comprisesisophorone diisocyanWe, meta-tetramethylxylylene diisocyanate(1,3-bis(1-isocyanato-1-methylethyl)-benzene), and/or methylenebis(4-cyclohexyldiisocyanate), available from Bayer Corporation asDESMODUR W.

Non-limiting examples of materials having isocyanate and isothiocyanategroups can include materials having aliphatic, alicyclic, aromatic orheterocyclic groups and which optionally contain sulfur atoms inaddition to those of the isothiocyanate groups. Non-limiting examples ofsuch materials can include 1-isocyanato-3-isothiocyanatopropane,1-isocyanato-5-isothiocyanatopentane,1-isocyanato-6-isothiocyanatohexane, isocyanatocarbonyl isothiocyanate,1-isocyanato-4-isothiocyanatocyclohexane,1-isocyanato-4-isothiocyanatobenzene,4-methyl-3-isocyanato-1-isothiocyanatobenzene,2-isocyanato-4,6-diisothiocyanato-1,3,5-triazine,4-isocyanato-4′-isothiocyanato-diphenyl sulfide and2-isocyanato-2′-isothiocyanatodiethyl disulfide.

Isocyanate groups may be blocked or unblocked as desired. If thepolyisocyanate is to be blocked or capped, any suitable aliphatic,cycloaliphatic, or aromatic alkyl monoalcohol or phenolic compound knownto those skilled in the art can be used as a capping agent for thepolyisocyanate.

The molecular weight of the polyisocyanate and polyisothiocyanate canvary widely. The number average molecular weight (Mn) of each can be atleast 100 grams/mole, or at least 150 grams/mole, or less than 15,000grams/mole, or less than 5000 grams/mole. The number average molecularweight can be determined using known methods. The number averagemolecular weight values recited herein and the claims were determined bygel permeation chromatography (GPC) using polystyrene standards.

The amount of polyisocyanate compound (A) and the amount of oligomericpolythiol (B), when used to prepare an isocyanate-terminatedpolyurethane prepolymer or sulfur-containing polyurethane prepolymer,can be selected such that the equivalent ratio of (NCO):(SH+OH) can begreater than 1.0:1.0, or at least 2.0:1.0, or at least 2.5:1.0, or lessthan 4.5:1.0, or less than 6.5:1.0. Likewise, in the preparation of aprepolymer, amount of polyisothiocyanate used as compound (A) and theamount of oligomeric polythiol (B) can be selected such that theequivalent ratio of (NCS):(SH+OH) can be greater than 1.0:1.0, or atleast 2.0:1.0, or at least 2.5:1.0, or less than 4.5:1.0, or less than6.5:1.0. The amount of a combination of polyisothiocyanate andpolyisocyanate used as compound (a) and the amount of oligomericpolythiol (b) in the preparation of a prepolymer can be selected suchthat the equivalent ratio of (NCS+NCO):(SH+OH) can be greater than1.0:1.0, or at least 2.0:1.0, or at least 2.5:1.0, or less than 4.5:1.0,or less than 6.5:1.0.

In embodiments wherein the reactive compound (A) comprisespolyisothiocyanate and/or polyisocyanate, there is often included in thereaction mixture a thermal stabilizer such as any of the antioxidants asare well known in the art. The thermal stabilizer can include aphosphite, for example a trisaryl phosphite, in particular,trisnonylphenyl phosphite, added as a stabilizer. The thermal stabilizermay be added to the reaction mixture at any phase of the reaction. Forexample, the thermal stabilizer may be added during the preparation ofthe oligomeric polythiol (B) and carried forward to the reaction withthe polyisocyanate and/or polyisothiocyanate. Alternatively, the thermalstabilizer may be mixed with the polyisocyanate and/orpolyisothiocyanate before reaction with compounds (B) and (C).

Polyepoxides and polyepisulfides are also suitable for use in thereactive compound (A). Examples of suitable polyepoxides include lowmolecular weight polyepoxides such as 3,4-epoxycyclohexylmethyl3,4-epoxycyclohexanecarboxylate andbis(3,4-epoxy-6-methylcyclohexyl-methyl)adipate. Higher molecular weightpolyepoxides, including polyglycidyl ethers of polyhydric phenols andalcohols, are also suitable.

Other specific examples of polyepoxide materials are disclosed in U.S.Pat. No. 5,369,141; U.S. Pat. No. 5,374,668; and elsewhere.Epoxide-containing materials are often produced by reacting compoundscontaining active hydrogens with epihalohydrin such as epichlorohydrinor epibromohydrin, using any method known in the art, including but notlimited to those procedures disclosed in U.S. Pat. No. 2,324,483 andU.S. Pat. No. 5,807,975. Non-limiting examples of classes of compoundscontaining active hydrogens that may be chain-extended with anepihalohydrin include compounds having two or more thiol groups,compounds having one or more amino groups, compounds having two or morehydroxyl groups, compounds having combinations of such groups, ormixtures of compounds containing such groups, the Bisphenols, thechlorinated Bisphenols, the brominated Bisphenols, the polyhydricphenols, and the Novolac resins. Epoxide-containing materials may alsobe produced by reacting ethylenically unsaturated compounds with anappropriate oxidizing agent, such as hydrogen peroxide ormeta-chloroperbenzoic acid. Suitable epoxide-containing materials ofthis type can include but are not limited to the diepoxide derived from4-vinyl-1-cyclohexene.

Non-limiting examples of aliphatic non-cyclic epoxide-containingmaterials include the diglycidyl ethers of ethylene glycol, butanediol,diethylene glycol, 1,2-ethanedithiol, and 2-mercaptoethyl sulfide.

Non-limiting examples of epoxide-containing materials containingnon-aromatic rings are the poly-epoxides of cyclic polyenes, includingbut not limited to the bis-epoxide of 4-vinyl-1-cyclohexene.

Non-limiting examples of epoxide-containing materials containingaromatic rings include the polyglycidyl ethers of Bisphenol A,tetrabromo-Bisphenol A, Bisphenol F, Bisphenol S, resorcinol,hydroquinone, and Novolac resin.

Suitable episulfide-containing materials can vary, and can include butare not limited to materials having two or more episulfide functionalgroups. For example, the episulfide-containing material can have two ormore moieties represented by the following graphic formula XV:

wherein X″ can be S or O; Y′″ can be C₁-C₁₀ alkyl, O, or S; p″ can be aninteger from 0 to 2, and q′″ can be an integer from 0 to 10. In anon-limiting embodiment, the numerical ratio of S is 50% or more, on theaverage, of the total amount of S and O constituting a three-memberedring.

The episulfide-containing material having two or more moietiesrepresented by the formula (VIII) can be attached to an acyclic and/orcyclic skeleton. The acyclic skeleton can be branched or unbranched, andit can contain sulfide and/or ether linkages. The episulfide-containingmaterial can be obtained by replacing the oxygen in an epoxyring-containing material using sulfur, thiourea, triphenylphosphinesulfide or other such reagents known in the art. Alkylsulfide-typeepisulfide-containing materials can be obtained by reacting variousknown polythiols with epichlorohydrin in the presence of an alkali toobtain an alkylsulfide-type epoxy material; and then replacing theoxygen in the epoxy ring as described above.

In alternate non-limiting embodiments, the cyclic skeleton can includethe following materials:

(a) an episulfide-containing material wherein the cyclic skeleton can bean alicyclic skeleton,

(b) an episulfide-containing material wherein the cyclic skeleton can bean aromatic skeleton, and

(c) an episulfide-containing material wherein the cyclic skeleton can bea heterocyclic skeleton including a sulfur atom as a hetero-atom.

Each of the above materials can contain a linkage of a sulfide, anether, a sulfone, a ketone, and/or an ester.

Non-limiting examples of suitable episulfide-containing materials havingan alicyclic skeleton can include 1,3- and1,4-bis(β-epithiopropylthio)cyclohexane, 1,3- and1,4-bis(β-epithiopropylthiomethyl)cyclohexane,bis[4-(β-epithiopropylthio)cyclohexyl]methane,2,2-bis[4-(β-epithiopropylthio)cyclohexyl]propane,bis[4-(β-epithiopropylthio)cyclohexyl]sulfide, 4-vinyl-1-cyclohexenediepisulfide, 4-epithioethyl-1-cyclohexene sulfide,4-epoxy-1,2-cyclohexene sulfide,2,5-bis(β-epithiopropylthio)-1,4-dithiane, and2,5-bis(β-epithiopropylthioethylthiomethyl)-1,4-dithiane.

Non-limiting examples of suitable episulfide-containing materials havingan aromatic skeleton can include 1,3- and1,4-bis(β-epithiopropylthio)benzene, 1,3- and1,4-bis(β-epithiopropylthiomethyl)benzene,bis[4-(β-epithiopropylthio)phenyl]methane,2,2-bis[4-(β-epithiopropylthio)phenyl]propane,bis[4-(β-epithiopropylthio)phenyl]sulfide,bis[4-(β-epithiopropylthio)phenyl]sulfone, and4,4-bis(β-epithiopropylthio)biphenyl.

Non-limiting examples of suitable episulfide-containing materials havinga heterocyclic skeleton including the sulfur atom as the hetero-atom caninclude the materials represented by the following general formulas:

wherein r can be an integer from 1 to 5; s can be an integer from 0 to4; a can be an integer from 0 to 5; U can be a hydrogen atom or an alkylgroup having 1 to 5 carbon atoms; Y″″ can be —(CH₂CH₂S)—; Z can bechosen from a hydrogen atom, an alkyl group having 1 to 5 carbon atomsor —(CH₂)_(r)SY″″_(s)W; W can be an epithiopropyl group represented bythe following graphic formula XIX:

wherein X″ can be O or S.

Additional non-limiting examples of suitable episulfide-containingmaterials can include 2,5-bis(β-epithiopropylthiomethyl)-1,4-dithiane;2,5-bis(β-epithiopropylthioethylthiomethyl)-1,4-dithiane;2,5-bis(β-epithiopropylthioethyl)-1,4-dithiane;2,3,5-tri(β-epithiopropylthioethyl)-1,4-dithiane;2,4,6-tris(β-epithiopropylthiomethyl)-1,3,5-trithiane;2,4,6-tris(β-epithiopropylthioethyl)-1,3,5-trithiane;2,4,6-tris(3-epithiopropylthiomethyl)-1,3,5-trithiane;2,4,6-tris(β-epithiopropylthioethylthioethyl)-1,3,5-trithiane; such asthe materials represented by graphic formulae XX, XXI, XXII and XXIII:

wherein X″ can be as defined above.

Polyacids, particularly polycarboxylic acids, are also suitable for usein the reactive compound (A). Non-limiting examples of unsaturatedpolycarboxylic acids, e.g., dicarboxylic acids, include maleic, fumaric,citraconic, itaconic and meconic acids, their anhydrides and their loweralkyl esters or acid halides. Non-limiting examples of saturatedpolycarboxylic acids include aliphatic dicarboxylic acids such asmalonic, succinic, glutaric, adipic, suberic, azelaic, pimelic andsebacic acids; aromatic acids such as orthophthalic, terephthalic,isophthalic acids and the anhydrides of such aromatic acids, such asphthalic anhydride and maleic anhydride, and the lower alkyl esters oracid halides of these acids or mixtures thereof. Non-limiting examplesof suitable cyclic anhydrides include tetrahydrophthalic anhydride,hexahydrophthalic anhydride, methyl hexahydrophthalic anhydride, maleicanhydride adduct of cyclopentadiene, maleic anhydride adduct ofmethylcyclopentadiene, chlorendic anhydride, pyromellitic dianhydride,and others disclosed in U.S. Pat. No. 5,369,141.

Mixtures of acids and/or anhydrides may also be used.

Polyethylenically unsaturated reactive compounds; i.e., materials havingmultiple ethylenically unsaturated groups (double bonds), areparticularly useful in compositions that cure using actinic radiation;e.g., UV curable compositions. Any of the materials disclosed abovehaving at least two double bonds is suitable. Polyvinyl ethers areexamples of suitable reactive compounds. Poly(meth)acrylate reactivecompounds include ethylene glycol di(meth)acrylate, tetraethylene glycoldi(meth)acrylate, glycerol di(meth)acrylate, glycerol tri(meth)acrylate,1,3-propylene glycol di(meth)acrylate, dipropylene glycoldi(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,2,4-butanetrioltri(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,4-cyclohexanedioldi(meth)acrylate, 1,4-benzenediol di(meth)acrylate, pentaerythritoltetra(meth)acrylate, 1,5-pentanediol di(meth)acrylate,trimethylolpropane di(meth)acrylate, and trimethylolpropanetri(meth)acrylate.

The optional compound (C) containing active hydrogens (which isdifferent from B), used to prepare the any of the compositions andarticles of the present invention, may be any compound or mixture ofcompounds that contain active hydrogens (e.g., active hydrogens ofhydroxyl, thiol or amino groups). The compound (C) may comprise acompound having at least two active hydrogens comprising primary aminegroups, secondary amine groups, hydroxyl groups, thiol groups, and/orcombinations thereof. A single polyfunctional compound having a singletype of functional group may be used; likewise, a single polyfunctionalcompound having mixed functional groups (e.g. hydroxyl and amino groups)may be used. Several different compounds may be used in admixture havingthe same or different functional groups; e.g., two different polyaminesmay be used, polythiols mixed with polyamines may be used, or polyaminesmixed with hydroxyl functional polythiols, for example, are suitable.

The compound (C) may have at least two primary and/or secondary aminegroups (polyamine). Non-limiting examples of suitable polyamines includeprimary or secondary diamines or polyamines in which the radicalsattached to the nitrogen atoms can be saturated or unsaturated,aliphatic, alicyclic, aromatic, aromatic-substituted-aliphatic,aliphatic-substituted-aromatic, and heterocyclic. Non-limiting examplesof suitable aliphatic and alicyclic diamines include 1,2-ethylenediamine, 1,2-propylene diamine, 1,8-octane diamine, isophorone diamine,propane-2,2-cyclohexyl amine, and the like. Non-limiting examples ofsuitable aromatic diamines include phenylene diamines and toluenediamines, for example o-phenylene diamine and p-tolylene diamine.Polynuclear aromatic diamines such as 4,4′-biphenyl diamine,4,4′-methylene dianiline and monochloro- and dichloro-derivatives of4,4′-methylene dianiline are also suitable.

Suitable polyamines for use in the present invention can include but arenot limited to materials having the following graphic formula XXIV:

wherein R₈ and R₉ can each be independently chosen from methyl, ethyl,propyl, and isopropyl groups, and R₁₀ can be chosen from hydrogen andchlorine. Non-limiting examples of polyamines for use in the presentinvention include the following compounds, manufactured by Lonza Ltd.(Base1, Switzerland):

LONZACURE® M-DIPA: R₈═C₃H₇; R₉═C₃H₇; R₁₀═H

LONZACURE® M-DMA: R₈═CH₃; R₉═CH₃; R₁₀═H

LONZACURE® M-MEA: R₈═CH₃; R₉═C₂H₅; R₁₀═H

LONZACURE® M-DEA: R₈═C₂H₅; R₉═C₂H₅; R₁₀═H

LONZACURE® M-MIPA: R₈═CH₃; R₉═C₃H₇; R₁₀═H

LONZACURE® M-CDEA: R₈═C₂H₅; R₉═C₂H₅; R₁₀═Cl

wherein R₈, R₉ and R₁₀ correspond to the aforementioned chemicalformula.

The polyamine can include a diamine reactive compound such as4,4′-methylenebis(3-chloro-2,6-diethylaniline), (Lonzacure® M-CDEA),which is available in the United States from Air Products and Chemical,Inc. (Allentown, Pa.); 2,4-diamino-3,5-diethyl-toluene,2,6-diamino-3,5-diethyl-toluene and mixtures thereof (collectively“diethyltoluenediamine” or “DETDA”), which is commercially availablefrom Albemarle Corporation under the trade name Ethacure 100;dimethylthiotoluenediamine (DMTDA), which is commercially available fromAlbemarle Corporation under the trade name Ethacure 300;4,4′-methylene-bis-(2-chloroaniline) which, is commercially availablefrom Kingyorker Chemicals as MOCA. DETDA can be a liquid at roomtemperature with a viscosity of 156 cPs at 25° C. DETDA can be isomeric,with the 2,4-isomer range being from 75 to 81 percent while the2,6-isomer range can be from 18 to 24 percent. The color stabilizedversion of Ethacure 100 (i.e., formulation which contains an additive toreduce yellow color), which is available under the name Ethacure 100Smay be used in the present invention.

Other examples of the polyamine can include ethyleneamines. Suitableethyleneamines can include but are not limited to ethylenediamine (EDA),diethylenetriamine (DETA), triethylenetetramine (TETA),tetraethylenepentamine (TEPA), pentaethylenehexamine (PEHA), piperazine,morpholine, substituted morpholine, piperidine, substituted piperidine,diethylenediamine (DEDA), and 2-amino-1-ethylpiperazine. In particularembodiments, the polyamine can be chosen from one or more isomers ofC₁-C₃ dialkyl toluenediamine, such as but not limited to3,5-dimethyl-2,4-toluenediamine, 3,5-dimethyl-2,6-toluenediamine,3,5-diethyl-2,4-toluenediamine, 3,5-diethyl-2,6-toluenediamine,3,5-diisopropyl-2,4-toluenediamine, 3,5-diisopropyl-2,6-toluenediamine,and mixtures thereof. Methylene dianiline and trimethyleneglycoldi(para-aminobenzoate) are also suitable.

Additional examples of suitable polyamines include methylene bisanilines, aniline sulfides, and bianilines, any of which may behetero-substituted, provided the substituents do not interfere with anyreactions to take place among the reactants. Specific examples include4,4′-methylene-bis(2,6-dimethylaniline),4,4′-methylene-bis(2,6-diethylaniline),4,4′-methylene-bis(2-ethyl-6-methylaniline),4,4′-methylene-bis(2,6-diisopropylaniline),4,4′-methylene-bis(2-isopropyl-6-methylaniline) and4,4′-methylene-bis(2,6-diethyl-3-chloroaniline).

Diamino toluenes such as diethyl toluene diamine (DETDA) are alsosuitable.

In certain embodiments when the reactive compound (A) comprisesisocyanate functionality, the amounts of (A), (B), and (C) can beselected such that the equivalent ratio of (NH+SH+OH):(NCO) can rangefrom 0.80:1.0 to 1.1:1.0, or from 0.85:1.0 to 1.0:1.0, or from 0.90:1.0to 1.0:1.0, or from 0.90:1.0 to 0.95:1.0, or from 0.95:1.0 to 1.0:1.0.

In embodiments wherein the reactive compound (A) comprisespolyisocyanate and/or polyisothiocyanate, the amounts of (A), (B), and(C) can be selected such that the equivalent ratio of(NH+SH+OH):(NCO+NCS) can range from 0.80:1.0 to 1.1:1.0, or from0.85:1.0 to 1.0:1.0, or from 0.90:1.0 to 1.0:1.0, or from 0.90:1.0 to0.95:1.0, or from 0.95:1.0 to 1.0:1.0.

The active hydrogen-containing compound (C) may have at least twoprimary and/or secondary hydroxyl, groups (polyol). Suitable polyolsinclude diols such as glycols and higher polyols. Hydroxyl functionalpolyesters as are known to those skilled in the art are also suitablefor use as the compound (C). In alternate non-limiting embodiments, theactive hydrogen-containing material for use in the present invention canbe chosen from polyether glycols and polyester glycols having a numberaverage molecular weight of at least 200 grams/mole, or at least 300grams/mole, or at least 750 grams/mole; or no greater than 1,500grams/mole, or no greater than 2,500 grams/mole, or no greater than4,000 grams/mole.

Any of the polythiols disclosed above, including the polythiols withhydroxyl functionality, are suitable for use as the compound (C).

Reaction of the various compounds (A), (B), and (C) may be enhanced withthe use of catalysts as can be determined by those skilled in the art.Suitable catalysts can be selected from those known in the art.Non-limiting examples can include tertiary amine catalysts,organophosphorus compounds, tin compounds, or mixtures thereof,depending on the nature of the various reactive components. In alternateembodiments, the catalysts can comprise dimethyl cyclohexylamine ordibutyl tin dilaurate or mixtures thereof. Degassing can take placeprior to or following addition of catalyst.

When the reactive compound (A) comprises a polyisocyanate, aurethanation catalyst can be used in the present invention to enhancethe reaction of the polyurethane-forming materials. Suitableurethanation catalysts can vary; for example, suitable urethanationcatalysts can include those catalysts that are useful for the formationof urethane by reaction of the NCO and OH-containing materials and/orthe reaction of the NCO and SH-containing materials. Non-limitingexamples of suitable catalysts can be chosen from the group of Lewisbases, Lewis acids and insertion catalysts as described in Ullmann'sEncyclopedia of Industrial Chemistry, 5^(th) Edition, 1992, Volume A21,pp. 673 to 674. The catalyst can be a stannous salt of an organic acid,such as but not limited to stannous octoate, dibutyl tin dilaurate,dibutyl tin diacetate, dibutyl tin mercaptide, dibutyl tin dimaleate,dimethyl tin diacetate, dimethyl tin dilaurate, dibutyltin dichloride,1,4-diazabicyclo[2.2.2]octane, and mixtures thereof. The catalyst canalternately be zinc octoate, bismuth, or ferric acetylacetonate.

Further non-limiting examples of suitable catalysts can include tincompounds such as dibutyl tin dilaurate, phosphines, tertiary ammoniumsalts and tertiary amines such as but not limited to triethylamine,triisopropylamine, dimethyl cyclohexylamine, N,N-dimethylbenzylamine andmixtures thereof. Such suitable tertiary amines are disclosed in U.S.Pat. No. 5,693,738 at column 10, lines 6-38, the disclosure of which isincorporated herein by reference.

When employed, the catalyst level can vary widely and can be dependentupon a variety of factors such as the type and amounts of the reactivecompounds used to prepare the compositions and articles of the presentinvention, as well as reaction conditions, speed of reaction, and degreeof reaction desired.

In an embodiment of the present invention wherein the optical article isa lens, the mixture, which can be optionally degassed, can be introducedinto a mold and the mold can be heated (i.e., using a thermal curecycle) using a variety of conventional techniques known in the art. Thethermal cure cycle can vary depending on the reactivity and molar ratioof the reactants, and the presence of catalyst(s). In particularembodiments, thermal cure cycle can include heating a mixture of apolyurethane prepolymer (reaction product of (A) and (B)) and anamine-containing curing agent compound (C), wherein the curing agent caninclude primary diamine or a mixture of primary diamine andtrifunctional or higher functional polyamine and optionally polyoland/or polythiol and/or polythiol oligomer; or heating the mixture ofpolyisocyanate and/or polyisothiocyanate, polyol and/or polythiol and/oroligomeric polythiol, and amine-containing material; from roomtemperature to a temperature of 200° C. over a period of from 0.5 hoursto 120 hours; or from 80 to 150° C. for a period of from 5 hours to 72hours.

Moreover, it should be noted that the base layer portion (a) of theoptical article of the present invention can be fully cured prior toforming the outer layer (b), or the base layer portion (a) can bepartially cured. If the base layer is only partially cured, aftercasting the outer layer (b) over the base layer (a), both layers arethen co-cured at a temperature and for a time sufficient to effectcuring of the outer layer (b).

The present invention is further drawn to rigid articles, such asoptical articles, comprising a reaction product of:

(A) a material having functional groups that are reactive with activehydrogens;

(B) a thioether-functional, oligomeric polythiol prepared by reactingtogether:

-   -   (1) a compound having at least two thiol functional groups; and    -   (2) a compound having triple bond functionality; and optionally

(C) a compound different from (B) containing active hydrogens.

Such articles may be prepared as described above to have any of thephysical properties previously mentioned.

In accordance with the present invention, there is also provided anarticle of manufacture, comprising a reaction product of:

(A) a reactive compound comprising a material having functional groupsthat are reactive with active hydrogens;

(B) a thioether-functional, oligomeric polythiol prepared by reactingtogether:

-   -   (1) a compound having at least two thiol functional groups;    -   (2) a compound having triple bond functionality; and optionally    -   (3) a compound having at least two double bonds; and,        optionally,

(C) a compound different from (B) containing active hydrogens.

Any of the materials disclosed above for (A), (B) and (C) may be used toprepare the articles of manufacture of the present invention. Sucharticles may include films, coatings, and molded items such as opticalarticles, in accordance with the present invention.

In a particular non-limiting embodiment of the present invention, areaction product comprising a sulfur-containing polyurethane can beprepared as follows:

1. A sulfur-containing polyurethane prepolymer is prepared by thereaction of:

A) at least one material comprising polyisocyanates,polyisothiocyanates, or mixtures thereof;

B) at least one polythiol comprising from any of the oligomericpolythiols of the present invention; and

C) optionally, other active hydrogen-containing material, comprisingpolyols, polythiols, or mixtures thereof.

2. Said sulfur-containing polyurethane prepolymer is mixed with at leastone material containing episulfide groups, epoxide groups, or mixturesof such groups.3. Sulfur-containing polyurethane is then prepared by the reaction of:

a) the product from step 2 above, and

b) at least one active hydrogen-containing material, comprising polyols,polythiols, or mixtures thereof.

In another particular non-limiting embodiment of the present invention,a reaction product comprising a sulfur-containing polyurethaneurea canbe prepared as follows:

1. A sulfur-containing polyurethane prepolymer is prepared by thereaction of:

A) at least one material comprising polyisocyanates,polyisothiocyanates, or mixtures thereof;

B) at least one polythiol comprising any of the oligomeric polythiols ofthe present invention;

C) optionally, other active hydrogen-containing material, comprisingpolyols, polythiols, or mixtures thereof.

2. Said sulfur-containing polyurethane prepolymer is mixed with at leastone material containing episulfide groups, epoxide groups, or mixturesof such groups.3. Sulfur-containing polyurethaneurea is then prepared by the reactionof:

a) the product from step 2 above;

b) a compound having at least two amine groups; and

c) optionally, active hydrogen-containing material, comprising polyols,polythiols, or mixtures thereof.

In alternate non-limiting embodiments, various known additives can beincorporated into the articles of the present invention. Such additivescan include but are not limited to light stabilizers, heat stabilizers,antioxidants, ultraviolet light absorbers, mold release agents, static(non-photochromic) dyes, pigments and flexibilizing additives, such asbut not limited to alkoxylated phenol benzoates and poly(alkyleneglycol) dibenzoates. Non-limiting examples of anti-yellowing additivescan include 3-methyl-2-butenol, organo pyrocarbonates and triphenylphosphite (CAS registry no. 101-02-0). Such additives can be present inan amount such that the additive constitutes less than 10 percent byweight, or less than 5 percent by weight, or less than 3 percent byweight, based on the total weight of the reaction product. Theaforementioned optional additives can be mixed with a polyisocyanateand/or polyisothiocyanate. Alternatively, the optional additives can bemixed with active hydrogen-containing material.

Polymeric Outer Layer

In preparation of the optical articles of the present invention, thepolymeric outer layer (b) is cast over the base layer (a). For example,in the instance where the optical article is a lens, the base layer (a)is prepared as described above in a glass mold. Once cured (either fullycured or partially cured), the front side of the mold can be opened toform a cavity between the front surface of the base layer (a) and theconcave inner surface of the glass mold. The reactants used to form theouter layer (b) are then injected into the cavity thereby forming aouter layer of uniform thickness over the surface of the base layer (a).Then the composite article thus formed is fully cured.

The polymeric outer layer (b) of the present invention is formed from apoly(urea-urethane) material having a refractive index of less than1.57, e.g., a refractive index ranging from 1.50 to 1.53. As previouslymentioned, the outer layer (b) has a thickness less than the thicknessof the base layer (a). For example, the outer layer (b) can have athickness ranging from 0.3 to 1.0 millimeter, such as from 0.5 to 1.0millimeter.

Suitable non-limiting examples of poly(urea-urethane) materials arethose comprising the reaction product of reactants comprising (a) atleast one polyol having greater than 1.0 hydroxyl groups per molecule,e.g., 1.1 hydroxyl groups; (b) at least one polyisocyanate havinggreater than 1.0 isocyanato groups per molecule; (c) at least onepolyamine having greater than 1.0 amino groups per molecule, each aminogroup being independently selected from primary amino and secondaryamino; and optionally, (d) at least one polyol having greater than 2.0hydroxyl groups per molecule; provided that the number of isocyanatogroups of the isocyanate reactants is greater than the number ofhydroxyl groups of the polyol reactants.

One polyol, e.g., diol, or more than one diol may be employed in formingthe poly(urea-urethane). The polyols which can be used are numerous andwidely varied. They are preferably substantially free from ethylenic oracetylenic unsaturation. The polyols which are used are most oftenaliphatic, alicyclic, aromatic, aliphatic-alicyclic, aliphatic-aromatic,alicyclic-aromatic, or aliphatic-alicyclic-aromatic in nature. Thepolyols are usually simple diols, e.g., diols having a molecular weightof less than 500 grams per mole, ester diols, polyester diols, etherdiols, polyether diols, or mixtures of such polyols. Although, otherkinds of diols can be employed as desired. The aliphatic groups of thediols can be straight or branched. Examples of such polyols aredisclosed in U.S. Pat. No. 5,684,083.

The aforedescribed polyols have greater than 1.0 hydroxyl groups permolecule, preferably greater than 1.5 hydroxyl groups per molecule, andmore preferably, at least 2.0 hydroxyl groups per molecule.

The diols which are employed, usually have a weight average molecularweight ranging from at least 62, preferably from 100, more preferablyfrom 200, and most preferably from at least 300. The weight averagemolecular weight of the diol is usually not more than 20,000, preferablynot more than 10,000, more preferably, not more than 8,000, and mostpreferably, not more than 2,000. For example, the weight averagemolecular weight of the diol may range from 400 to 1,500. The weightaverage molecular weight of the diol may range between any combinationof these values, inclusive of the recited values.

Examples of suitable diols include:

-   1,2-ethanediol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol,-   1,4-butanediol, 1,5-pentanediol, 2,2-dimethylpropane-1,3-diol,-   2-butyl-2-ethylpropane-1,3-diol, 1,5-hexanediol, 1,6-hexanediol,-   1,8-octanediol, 1,10-decanediol, 1,12-dodecanediol,-   2,2,4,4-tetramethylcyclobutane-1,3-diol, 1,3-cyclopentanediol,-   1,2-cyclohexanediol, 1,3-cyclohexanediol, 1,4-cyclohexanediol,-   1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol,-   1,4-cyclohexanedimethanol, and 1,4-cyclohexanediethanol.

Other examples include the polyalkylene glycols such as: diethyleneglycol, triethylene glycol, tetraethylene glycol, higher poly(ethyleneglycol), such as those having number average molecular weights of from220 to 2000, dipropylene glycol, tripropylene glycol, and higherpoly(propylene glycol) such as those having number average molecularweights of from 234 to 2000.

Yet other examples of suitable diols include

-   4,4′-(1-methylethylidene)bis[cyclohexanol],    2,2′-methylenebis[phenol],-   4,4′-methylenebis[phenol], 4,4′-(phenylmethylene)bis[phenol],-   4,4′-(diphenylmethylene)bis[phenol],    4,4′-(1,2-ethanediyl)bis[phenol],-   4,4′-(1,2-cyclohexanediyl)bis[phenol],    4,4′-(1,3-cyclohexanediyl)bis[phenol],-   4,4′-(1,4-cyclohexanediyl)bis[phenol], 4,4′-ethylidenebis[phenol],-   4,4′-(1-phenylethylidene)bis[phenol], 4,4′-propylidenebis[phenol],-   4,4′-cyclohexylidenebis[phenol],    4,4′-(1-methylethylidene)bis[phenol],-   4,4′-(1-methylpropylidene)bis[phenol],    4,4′-(1-ethylpropylidene)bis[phenol],-   4,4′-cyclohexylidenebis[phenol],-   4,4′-(2,4,8,10-tetraoxaspiro[5.5]undecane-3,9-diyldi-2,1-ethanediyl)bis[phenol],    1,2-benzenedimethanol, 1,3-benzenedimethanol,-   1,4-benzenedimethanol,-   4,4′-[1,3-phenylenebis(1-methylethylidene)]bis[phenol],-   4,4′-[1,4-phenylenebis(1-methylethylidene)]bis[phenol],    phenolphthalein,-   4,4′-(1-methylidene)bis[2-methylphenol],-   4,4′-(1-methylethylidene)bis[2-(1-methylethyl)phenol],-   2,2′-methylenebis[4-methyl-6-(1-methylethyl)phenol],

Ester diols, perhaps best exemplified by

-   3-hydroxy-2,2-dimethylpropyl 3-hydroxy-2,2-dimethylpropanoate, can    be employed.

Polyester diols constitute yet another class of diols which can be used.The polyester diols which are employed usually have a weight averagemolecular weight in the range of from 200 to 1200. Often the polyesterdiols have a weight average molecular weight in the range of from 300 to1000.

One type of polyester diol that can be used is that prepared by thereaction of a diol and a dicarboxylic acid. While any of the diolsdescribed above can be used, the simpler diols such as 1,6-hexanediol or1,10-decanediol are preferred. Exemplary dicarboxylic acids include:malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid,suberic acid, azelaic acid, sebacic acid, phthalic acid, isophthalicacid, and terephthalic acid.

Anhydrides, where they exist can be used in lieu of the correspondingdicarboxylic acids.

Another type of polyester diol that can be used is poly(caprolactonediol), which is the reaction product of one or more diols andε-caprolactone. While any of the diols described above can be used inthat reaction, the simpler diols such as 1,2-ethanediol, 1,4-butanediol,2,2-dimethylpropane-1,3-diol, 1,6-hexanediol, 1,10-decanediol,1,12-dodecanediol and diethylene glycol are most often used. U.S. Pat.No. 3,169,945, describes many suitable diols and their reaction withε-caprolactone.

Polyether diols are commonly made by polymerizing one or more cyclicethers such as epoxides (e.g., ethylene oxide, propylene oxide),oxetanes, oxolanes (e.g., tetrahydrofuran), or the like, in the presenceof water or a diol starter. The polyether diols are made using anysuitable catalyst, including, for example, potassium hydroxide, borontrifluoride, or a double metal cyanide. Double metal cyanide catalystsare preferred because they easily give polyether diol's withexceptionally low unsaturation or monol content. The diols can behomopolymers (e.g., poly(oxypropylene) diols), random copolymers of twoor more cyclic ethers (e.g., a random copolymer of propylene oxide andethylene oxide), block copolymers (e.g., a poly(oxypropylene) core withpoly(oxyethylene) caps, “tipped” copolymers (e.g., apoly(oxypropylene-co-oxyethylene core having one oxypropylene tooxyethylene ratio, which core is tipped withpoly(oxypropylene-co-oxyethylene) having a different oxypropylene tooxyethylene ratio.

Usually, but not necessarily, the polyether diol has a weight averagemolecular weight in the range of from 1500 to 20,000. Often the weightaverage molecular weight is in the range of from 2000 to 10,000.Preferably the weight average molecular weight is in the range of from2000 to 8000.

The actual hydroxyl functionality of polyether diols usually varies andoften depends on the nature of the catalyst used to make the polyetherdiol. While a polyether diol made by conventional KOH catalysistypically has an actual hydroxyl functionality of only about 1.6 or 1.7,one made using double metal cyanide catalyst may have an actual hydroxylfunctionality very close to 2.

In one contemplated embodiment, the polyether diols for use in thepresent invention have low unsaturations. In particular, the polyetherdiols have unsaturations less than 0.02 meq/g. Frequently theunsaturation is less than 0.01 meq/g and sometimes the unsaturation isless than 0.007 meq/g.

These polyether diols can be made by various known methods, includinguse of double metal cyanide catalysts, as described in U.S. Pat. Nos.5,158,922; 5,470,813; and 5,482,908.

One polyisocyanate having greater than 1.0 isocyanato groups permolecule, e.g., 1.5 groups per molecule, or a mixture, of more than onesuch polyisocyanate may be used in forming the poly(urea-urethane). Inmost instances, the polyisocyanate, has at least two isocyanato groups.When a mixture of polyisocyanates is employed and when some have morethan two isocyanato groups, the mixture usually (but not necessarily)contains one or more polyisocyanates having two isocyanato groups. Inmost instances the average isocyanato functionality is in the range offrom 2 to 4 isocyanato groups per molecule. Frequently the averageisocyanato functionality is in the range of from 2 to 3 isocyanatogroups per molecule. In many instances the average isocyanatofunctionality is in the range of from 2 to 2.5 isocyanato groups permolecule. Preferably the average isocyanato functionality is 2isocyanato groups per molecule.

The polyisocyanates which can be used are numerous and widely varied.Examples of types and classes of polyisocyanates include aliphaticpolyisocyanates, alicyclic polyisocyanates where one or more isocyanatogroups are attached directly to the ring, alicyclic polyisocyanateswhere one or more isocyanato groups are not attached directly to thering, aromatic polyisocyanates where one or more isocyanato groups areattached directly to the ring, aromatic polyisocyanates where one ormore isocyanato groups are not attached directly to the ring, hybrids ofany of the foregoing and mixtures of such polyisocyanates.

Representative examples of suitable polyisocyanates include, but are notlimited to:

-   1,2-diisocyanatoethane, 1,2-diisocyanatopropane,-   1,3-diisocyanatopropane, 1,2-diisocyanato-2-methylpropane,-   1,2-diisocyanatobutane, 1,3-diisocyanatobutane,-   1,4-diisocyanatobutane, 1,5-diisocyanatopentane,-   1,6-diisocyanatohexane, 1,7-diisocyanatoheptane,-   1,8-diisocyanatooctane, 1,9-diisocyanatononane,-   1,10-diisocyanatodecane, 1,5-diisocyanato-2,2-dimethylpentane,-   ethylidine diisocyanate, butylidene diisocyanate,-   bis(2-isocyanatoethyl)ether, 1,2-diisocyanatocyclopentane,-   1,3-diisocyanatocyclopentane, 1,2-diisocyanatocyclohexane,-   1,3-diisocyanatocyclohexane, 1,4-diisocyanatocyclohexane,-   bis(4-isocyanatocyclohexyl)ether,-   1-(isocyanatomethyl)-5-isocyanato-1,3,3-trimethylcyclohexane,-   1-(isocyanatomethyl)-1-(3-isocyanatopropyl)cyclohexane,-   bis(2-isocyanatocyclohexyl)methane,    bis(3-isocyanatocyclohexyl)methane,-   bis(4-isocyanatocyclohexyl)methane,-   1,2-bis(2-isocyanatocyclohexyl)ethane,-   1,2-bis(3-isocyanatocyclohexyl)ethane,-   1,2-bis(4-isocyanatocyclohexyl)ethane,-   2,2-bis(4-isocyanatocyclohexyl)propane,-   2,3-bis(8-isocyanatooctyl)-4-octyl-5-hexylcyclohexene,-   1,2-diisocyanatobenzene, 1,3-diisocyanatobenzene,-   1,4-diisocyanatobenzene, 1,4-diisocyanato-2-ethylbenzene,-   1,3-diisocyanato-5-(1-methylethyl)benzene,-   1,2-dimethyl-3,5-diisocyanatobenzene,-   1,3-bis(1-isocyanato-1-methylethyl)benzene,-   1,4-bis(1-isocyanato-1-methylethyl)benzene,-   bis(2-isocyanatophenyl)methane, bis(3-isocyanatophenyl)methane,-   bis(4-isocyanatophenyl)methane,-   1,2-bis(2-isocyanatophenyl)ethane,-   1,2-bis(3-isocyanatophenyl)ethane,-   1,2-bis(4-isocyanatophenyl)ethane,-   4,4′-diisocyanatobiphenyl, 1,4-diisocyanatonaphthalene,-   1,5-diisocyanatonaphthalene, 1,5-bis(isocyanatomethyl)naphthalene,-   2,4-diisocyanatotoluene, 2,6-diisocyanatotoluene,-   1,2-bis(isocyanatomethyl)benzene, 1,3-bis(isocyanatomethyl)benzene,-   1,4-bis(isocyanatomethyl)benzene,-   1,2-bis(2-isocyanatoethyl)benzene,-   1,3-bis(2-isocyanatoethyl)benzene,-   1,4-bis(2-isocyanatoethyl)benzene,-   1,2-bis(1-isocyanato-1-methylethyl)benzene,-   1,3-bis(1-isocyanato-1-methylethyl)benzene,-   1,4-bis(1-isocyanato-1-methylethyl)benzene,-   1,2-bis(4-isocyanatobutyl)benzene,-   1,3-bis(4-isocyanatobutyl)benzene,-   1,4-bis(4-isocyanatobutyl)benzene,-   bis(4-isocyanatophenyl)ether, bis(4-isocyanatomethylphenyl)ether,-   3,3′-diisocyanatobiphenyl, 4,4′-diisocyanatobiphenyl,-   4,4′-diisocyanato-2,2′-dimethylbiphenyl,-   4,4′-diisocyanato-3,3′-dimethylbiphenyl,-   4,4′-diisocyanato-2,2′-dimethoxybiphenyl,-   4,4′-diisocyanato-3,3′-dimethoxybiphenyl,-   2,5-bis(isocyanatomethyl)furan, tris(4-isocyanatophenyl)methane,-   tris(4-isocyanatocyclohexyl)methane,-   1,3,5-triisocyanatobenzene, 2,4,6-triisocyanatotoluene,-   2,4,6-triisocyanatomesitylene, 1,3,5-tris(6-isocyanatohexyl)biuret,-   2,4,6-triisocyanato-1,3,5-triazine,-   2-isocyanatomethyl-2-(3-isocyanatopropyl)-5-isocyanatomethyl-bicyclo[2.2.1]heptane,-   2-isocyanatomethyl-3-(3-isocyanatopropyl)-5-isocyanatomethyl-bicyclo[2.2.1]heptane,-   2-isocyanatomethyl-2-(3-isocyanatopropyl)-6-isocyanatomethyl-bicyclo[2.2.1]heptane,-   2-isocyanatomethyl-3-(3-isocyanatopropyl)-6-isocyanatomethyl-bicyclo[2.2.1]heptane,-   2-isocyanatomethyl-2-(3-isocyanatopropyl)-5-(2-isocyanatoethyl)bicyclo[2.2.1]heptane,-   2-isocyanatomethyl-3-(3-isocyanatopropyl)-6-(2-isocyanatoethyl)bicyclo[2.2.1]heptane,-   2-isocyanatomethyl-2-(3-isocyanatopropyl)-6-(2-isocyanatoethyl)bicyclo[2.2.1]heptane,-   bis(2,5-diisocyanato-4-methylcyclohexyl)methane,-   bis(2,5-diisocyanato-4-methylphenyl)methane,-   polymeric polyisocyanates such as dimers and trimers, and    prepolymers    which are derived from a polyol, including a hydrocarbon polyol, a    polyether polyol, a polyester polyol or mixtures of such polyols. An    example is an adduct (approximately 3:1, molar) of-   1-isocyanatomethyl-5-isocyanato-1,3,3-trimethylcyclohexane and-   2-ethyl-2-(hydroxymethyl)-1,3-propanediol.

In one contemplated embodiment, the polyisocyanate isbis(4-isocyanatocyclohexyl)methane. The trans-trans isomer, thecis-trans isomer or the cis-cis isomer may be used either alone or incombination with either or both of the other isomers; however, thetrans-trans isomer is preferred. In most instances the trans-transisomer constitutes from 20 to 100 percent of thebis(4-isocyanatocyclohexyl)methane. It is especially preferred that thebis(4-isocyanatocyclohexyl)-methane contain at least about 50 percent ofthe trans-trans isomer and no more than 20 percent of the cis-cisisomer.

The polyamine has greater than 1.0 amino groups per molecule, each aminogroup being independently selected from primary amino (—NH₂) orsecondary amino (—NH—). In one contemplated embodiment, all of the aminogroups are primary amino. The polyamine reactant may be selected fromaliphatic polyamines, cycloaliphatic polyamines, aromatic polyamines andpolyamines of mixed aliphatic, cycloaliphatic, and/or aromatic types, ormixtures thereof. Preferably the polyamine reactant has at least twoprimary amino groups.

The polyamines which can be used are numerous and widely varied.Examples of suitable diamines include, but are not limited to:

-   1,2-ethanediamine, 1,3-propanediamine,-   1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine,-   1,7-heptanediamine, 1,8-octanediamine, 1,9-nonanediamine,-   1,10-decanediamine, 1,2-benzenediamine, 1,3-benzenediamine,-   1,4-benzenediamine, 1,5-naphthalenediamine, 1,8-naphthalenediamine,-   2,4-toluenediamine,-   2,5-toluenediamine, 3,3′-dimethyl-4,4′-biphenyldiamine,-   4,4′-methylenebis[aniline], 4,4′-methylenebis[2-chloroaniline],-   4,4′-oxybis[aniline], [1,1′-biphenyl]-4,4′-diamine,-   [1,1′-biphenyl]-3,3′-dichloro-4,4′-diamine,-   6-phenyl-1,3,5-triazine-2,4-diamine, and-   piperazine.

The polyamine reactant may also be selected from one or more isomers ofC₁-C₃ dialkyl toluenediamine, such as for example:

-   3,5-dimethyl-2,4-toluenediamine,-   3,5-dimethyl-2,6-toluenediamine, 3,5-diethyl-2,4-toluenediamine,-   3,5-diethyl-2,6-toluenediamine,-   3,5-diisopropyl-2,4-toluenediamine,-   3,5-diisopropyl-2,6-toluenediamine.    A preferred embodiment is an isomeric mixture containing mostly-   3,5-diethyl-2,4-toluenediamine and 3,5-diethyl-2,6-toluenediamine.

In one embodiment of the present invention, the polyamine reactant canbe selected from one or more diamines represented by Formula (I):

wherein R₃ and R₄ are each independently C₁-C₃ alkyl, and R₅ is selectedfrom hydrogen and halogen, e.g., chlorine and bromine. The diaminerepresented by Formula (I) can be described generally as a4,4′-methylene-bis(dialkylaniline). Specific examples of diaminesrepresented by Formula (I) include, but are not limited to:

-   4,4′-methylenebis[2,6-dimethylaniline],-   4,4′-methylenebis[2,6-d iethylaniline],-   4,4′-methylenebis[2-ethyl-6-methylaniline],-   4,4′-methylenebis[2,6-diisopropylaniline],-   4,4′-methylenebis[2-isopropyl-6-methylaniline], and-   4,4′-methylenebis[2,6-diethyl-3-chloroaniline].    A preferred diamine represented by Formula (I) is-   4,4′-methylenebis[2,6-diethyl-3-chloroaniline].

The polyamine may contain more than two amino groups. Examples include:diethylenetriamine, triethylenetetramine, tetraethylenepentamine,pentaethylenehexamine, 2-amino-1-ethylpiperazine, andN,N′-bis(3-aminopropylene)piperazine.

One or more polyols having greater than 2.0 hydroxyl groups per moleculemay optionally be used in forming the poly(urea-urethane). Such polyolsinclude the triols, tetrols, or higher functional polyols. These polyolsare numerous and widely varied. Examples include, but are not limitedto:

-   glycerol, 1,1,1-trimethylolethane, 1,1,1-trimethylolpropane,-   1,2,3-benzenetriol, 1,2,4-benzenetriol, 1,3,5-benzenetriol,-   1,3,5-cyclohexanetriol, erythritol, pentaerythritol,-   4,4′-(1,2-diethyl-1,2-dihydroxyethanediyl)bis[phenol],-   sorbitol, mannitol, α-methylglucoside, sorbitan, dipentaerythritol,-   tripentaerythritol and mixtures thereof.

Generally, but not necessarily, the polyol having greater than 2.0hydroxyl groups has an average hydroxyl functionality of three hydroxylgroups per molecule. When a polyol having at least three hydroxyl groupsis employed, it is used in minor amount. For convenience and economy ofspace, the diol and the polyol having greater than 2.0 hydroxyl groupswill be collectively referred to herein as “total polyol”. In mostinstances the ratio of the hydroxyl equivalents of polyol having greaterthan 2.0 hydroxyl groups to the hydroxyl equivalents of diol havinggreater than 1.0 hydroxyl groups present in the total polyol is in therange of from 0 to 0.25:1. Often the ratio is in the range of from 0 to0.2:1. In one contemplated embodiment, the ratio is in the range of from0.01:1 to 0.2:1. In another contemplated embodiment, the ratio is in therange of 0.05:1 to 0.1:1.

Usually the average isocyanato functionality of the polyisocyanatehaving greater than 1.0 isocyanato groups used in preparing thepoly(urea-urethane) is in the range of from 2 to 3 isocyanato groups permolecule. In one contemplated embodiment, the polyisocyanate has anaverage isocyanato functionality of 2 isocyanato groups per molecule.

In most instances the average amino functionality of the polyaminehaving greater than 1.0 amino groups per molecule used in preparing thepoly(urea-urethane) is in the range of from 2 to 4 amino groups permolecule. In one contemplated embodiment, the polyamine has an averageamino functionality of 2 amino groups per molecule.

It is also preferred to use an aromatic polyamine that has relativelylow yellowness. A low-yellowness polyamine will tend to give lowyellowness poly(urea-urethanes). Low-yellowness polyamines (especiallylow-yellowness diamines) are available commercially. Alternatively, theyellowness of aromatic polyamines with higher yellowness can be reducedby conventional means (e.g., distillation, carbon treatment, addition ofreducing agents, and the like).

The polymerizates of this invention can be prepared by the one shot,quasi-prepolymer, or full prepolymer methods, all of which are wellknown in the art. Of these, the full prepolymer method is preferred.

In the preferred process for making the poly(urea-urethanes), aprepolymer is first made by reacting the polyisocyanate and the totalpolyol at an NCO/OH equivalent ratio in the range of from 1.3:1 to4.5:1. Preferably the NCO/OH equivalent ratio is in the range of from2.4:1 to 4:1. The reaction may conveniently be conducted at temperaturesin the range of from 40° C. to 145° C. under a blanket of unreactive gassuch as nitrogen or helium. Often the temperature is in the range offrom 70° C. to 135° C. Frequently the temperature is in the range offrom 90° C. to 130° C. Either or both of the reactants may be fed to thereaction mixture during the reaction, but it is more usual to simplyadmix the reactants and then heat the mixture to reaction temperatureunder a blanket of unreactive gas and maintain the reaction mixture atthe reaction temperature for a period in the range of from 10 to 60minutes. In general, higher reaction temperatures favor shorter reactionperiods.

Although no catalyst is required during prepolymer formation, the use ofa catalyst is often desirable. When a catalyst is used, it is preferablyan organometallic catalyst, such as, for example, an organometallic tin,lead, iron, bismuth, or mercury compound. Organotin compounds such asdibutyltin dilaurate are preferred. Delayed-action catalysts can also beused. Other suitable catalysts are described in U.S. Pat. No. 5,646,230.When a catalyst is used, it is ordinarily used in an amount in the rangeof from 25 to 1000 parts per million of total reactants, by weight.Inasmuch as the polyisocyanate is used in excess, the product is anisocyanate-terminated prepolymer.

Small additional amounts of polyisocyanate may optionally be added tothe prepolymer when it is desired to increase the isocyanato content.

In one contemplated embodiment, the polyamine, photochromic compound(s)and the prepolymer are admixed to form a reaction mixture which isapplied as a coating to a substrate or poured into a preheated mold andcured to form a photochromic poly(urea-urethane) article. In anothercontemplated embodiment, the mold is a lens mold and thepoly(urea-urethane) article is a photochromic ophthalmic lens. Informing the reaction mixture, the polyamine and the prepolymer areadmixed at an amine/NCO equivalent ratio in the range of from 0.85:1 to1.2:1. Often the amine/NCO equivalent ratio is in the range of from0.9:1 to 1.1:1. In many instances the amine/NCO equivalent ratio is inthe range of from 0.9:1 to 1.05:1. Preferably the amine/NCO equivalentratio is in the range of from 0.92:1 to 1:1.

Alternatively, the poly(urea-urethane) may be prepared by aquasi-prepolymer method of reacting the polyisocyanate with 0.3 to 0.8equivalents of the total polyol to form a prepolymer, and then theremaining 0.2 to 0.7 equivalents of the total polyol are added with thediamine curing agent.

The curing reaction may conveniently be conducted at temperatures in therange of from 40° C. to 135° C. Often the temperature is in the range offrom 45° C. to 110° C. Frequently the temperature is in the range offrom 50° C. to 100° C. The curing period is usually in the range of from3 minutes to 24 hours, depending upon the rate of reaction between theamino groups of the polyamine and the isocyanato groups of theprepolymer. Optionally, once the poly(urea-urethane)outer layer (b) issolid enough to hold its shape, the optical article may be removed fromthe mold and post-cured by heating it in an oven e.g., for several hours(or even overnight). Typically, the potlife of the reaction mixture usedto form the outer layer (a) (that is, the maximum time the formulatorhas to fill the mold with the reaction mixture after admixing thepolyamine, photochromic compounds and the prepolymer) is at least 20seconds, for example at least 30 seconds.

Various conventional additives may be incorporated into the reactionmixture used to form outer layer (a). Such additives may include lightstabilizers, heat stabilizers, antioxidants, ultraviolet lightabsorbers, mold release agents, static (non-photochromic) dyes,pigments, and flexibilizing additives, e.g., alkoxylated phenolbenzoates and poly(alkylene glycol)dibenzoates. Antiyellowing additives,e.g., 3-methyl-2-butenol, organo pyrocarbonates and triphenyl phosphite,may also be added to enhance resistance to yellowing. Such additives aretypically present in amounts totaling 10% or less by weight, preferablyless than 5% by weight, and more preferably less than 3% by weight,based on the total weight of the combined polyamine and prepolymer.While such conventional additives may be added to either the prepolymeror the polyamine, they are preferably incorporated into the polyamine.

Specific stabilizers contemplated for use in combination with theorganic photochromic compounds described hereinafter include thosehindered amine light stabilizer (HALS) materials reported to function asradical scavengers and that contain a 2,2,6,6-tetramethylpiperidine ringor 2,2,6,6-tetramethylpiperazinone. Such stabilizers are typically usedin an amount of from 0.01 to 10 weight percent, based on the totalweight or the organic resin composition.

In one contemplated embodiment, the following HALS materials can be usedwith the photochromic compounds incorporated into the organic resincomposition individually or in combination:bis(1,2,2,6,6-pentamethyl-4-piperidinyl)[3,5-bis(1,1-dimethylethyl-4-hydroxyphenyl)methyl]butylpropanedioate; bis(1,2,2,6,6-pentamethyl-4-piperidinyl)sebacate andmethyl(1,2,2,6,6-pentamethyl-4-piperidinyl sebacate; and N-unsubstitutedHALS materials, e.g., SANDUVOR 3051, 3052 and 3055.

The general preparation of poly(urea-urethane) is described in U.S. Pat.Nos. 3,866,242; 5,811,506; 5,962,617; and 5,962,619.

In a particular embodiment of the present invention the outer layer (b)comprises the reaction product of:

-   -   (a) a prepolymer having isocyanate functional groups comprising        the reaction product of:        -   (i) at least one polyol selected from simple diols, ester            diols, polyester diols (such as poly(caprolactone diol)),            polyether diols, or mixtures thereof.        -   (ii) at least one polyisocyanate such as any of those            described above; and    -   (b) at least one polyamine such as any of those described above,        for example an aromatic polyamine. The number of isocyanato        groups of the polyisocyanate reactants is greater than the        number of hydroxyl groups of the polyol reactants.

As previously mentioned, the outer layer (b) additionally comprises aphotochromic material and/or a static dye. The photochromic materialsmay be provided in a variety of forms. Examples include: a singlephotochromic compound; a mixture of photochromic compounds; a materialcontaining a photochromic compound, such as a monomeric or polymericungelled solution; a material such as a monomer or polymer to which aphotochromic compound is chemically bonded; a material comprising and/orhaving chemically bonded to it a photochromic compound, the outersurface of the material being encapsulated (encapsulation is a form ofcoating), for example with a polymeric resin or a protective coatingsuch as a metal oxide that prevents contact of the photochromic materialwith external materials such as oxygen, moisture and/or chemicals thathave a negative effect on the photochromic material; such materials canbe formed into a particulate prior to applying the protective coating asdescribed in U.S. Pat. Nos. 4,166,043 and 4,367,170; a photochromicpolymer, e.g., a photochromic polymer comprising photochromic compoundsbonded together; or mixtures thereof.

The inorganic photochromic material may contain crystallites of silverhalide, cadmium halide and/or copper halide. Other inorganicphotochromic materials may be prepared by the addition of europium (II)and/or cerium (III) to a mineral glass such as a soda-silica glass.

The photochromic material may be an organic photochromic material havingan activated absorption maxima in the range from 300 to 1000 nanometers.In one embodiment, the organic photochromic material comprises a mixtureof (a) an organic photochromic material having a visible lambda max offrom 400 to less than 550 nanometers, and (b) an organic photochromicmaterial having a visible lambda max of from 550 to 700 nanometers.

The photochromic material may alternatively comprise an organicphotochromic material that may be chosen from pyrans, oxazines,fulgides, fulgimides, diarylethenes and mixtures thereof.

Non-limiting examples of photochromic pyrans that may be used hereininclude benzopyrans, and naphthopyrans, e.g., naphtho[1,2-b]pyrans,naphtho[2,1-b]pyrans, indeno-fused naphthopyrans and heterocyclic-fusednaphthopyrans, spiro-9-fluoreno[1,2-b]pyrans, phenanthropyrans,quinolinopyrans; fluoroanthenopyrans and spiropyrans, e.g.,spiro(benzindoline)naphthopyrans, spiro(indoline)benzopyrans,spiro(indoline)naphthopyrans, spiro(indoline)quinolinopyrans andspiro(indoline)pyrans and mixtures thereof. Non-limiting examples ofbenzopyrans and naphthopyrans are disclosed in U.S. Pat. No. 5,645,767at column 2, line 16 to column 12, line 57; U.S. Pat. No. 5,723,072 atcolumn 2, line 27 to column 15, line 55; U.S. Pat. No. 5,698,141 atcolumn 2, line 11 to column 19, line 45; U.S. Pat. No. 6,022,497 atcolumn 2, line 21 to column 11, line 46; U.S. Pat. No. 6,080,338 atcolumn 2, line 21 to column 14, line 43; U.S. Pat. No. 6,136,968 atcolumn 2, line 43 to column 20, line 67; U.S. Pat. No. 6,153,126 atcolumn 2, line 26 to column 8, line 60; U.S. Pat. No. 6,296,785 atcolumn 2, line 47 to column 31, line 5; U.S. Pat. No. 6,348,604 atcolumn 3, line 26 to column 17, line 15; U.S. Pat. No. 6,353,102 atcolumn 1, line 62 to column 11, line 64; U.S. Pat. No. 6,630,597 atcolumn 2, line 16 to column 16, line 23; and U.S. Pat. No. 6,736,998 atcolumn 2, line 53 to column 19, line 7, the cited portions of which areincorporated herein by reference. Further non-limiting examples ofnaphthopyrans and complementary organic photochromic substances aredescribed in U.S. Pat. No. 5,658,501 at column 1, line 64 to column 13,line 17, which disclosure is incorporated herein by reference.Spiro(indoline)pyrans are also described in the text, Techniques inChemistry, Volume III, “Photochromism”, Chapter 3, Glenn H. Brown,Editor, John Wiley and Sons, Inc., New York, 1971.

Examples of photochromic oxazines that may be used include benzoxazines,naphthoxazines, and spiro-oxazines, e.g., spiro(indoline)naphthoxazines,spiro(indoline)pyridobenzoxazines,spiro(benzindoline)pyridobenzoxazines,spiro(benzindoline)naphthoxazines, spiro(indoline)benzoxazines,spiro(indoline)fluoranthenoxazine, spiro(indoline)quinoxazine andmixtures thereof.

Examples of photochromic fulgides or fulgimides that may be usedinclude: fulgides and fulgimides, which are disclosed in U.S. Pat. No.4,685,783 at column 1, line 57 to column 5, line 27, and in U.S. Pat.No. 4,931,220 at column 1, line 39 through column 22, line 41, thedisclosure of such fulgides and fulgimides are incorporated herein byreference. Non-limiting examples of diarylethenes are disclosed in U.S.Patent Application 2003/0174560 paragraphs [0025] to [0086].

Polymerizable organic photochromic materials, such as polymerizablenaphthoxazines disclosed in U.S. Pat. No. 5,166,345 at column 3, line 36to column 14, line 3; polymerizable spirobenzopyrans disclosed in U.S.Pat. No. 5,236,958 at column 1, line 45 to column 6, line 65;polymerizable spirobenzopyrans and spirobenzothiopyrans disclosed inU.S. Pat. No. 5,252,742 at column 1, line 45 to column 6, line 65;polymerizable fulgides disclosed in U.S. Pat. No. 5,359,085 at column 5,line 25 to column 19, line 55; polymerizable naphthacenediones disclosedin U.S. Pat. No. 5,488,119 at column 1, line 29 to column 7, line 65;polymerizable spirooxazines disclosed in U.S. Pat. No. 5,821,287 atcolumn 3, line 5 to column 11, line 39; polymerizable polyalkoxylatednaphthopyrans disclosed in U.S. Pat. No. 6,113,814 at column 2, line 23to column 23, line 29; and the polymeric matrix compatibilizednaphthopyran of U.S. Pat. No. 6,555,028 at column 2, line 40 to column24, line 56 may be used. The disclosures of the aforementioned patentson polymerizable organic photochromic materials are incorporated hereinby reference.

The photochromic materials can be incorporated into the outer layer (b)of the optical article, by various means. For example, the photochromicmaterials may be incorporated, e.g., dissolved and/or dispersed, intothe composition, or polymerized with other components of the compositionused to form the outer layer (b). Alternatively, the photochromicmaterials may be incorporated into the outer layer (b) by imbibition,permeation or other transfer methods as known by those skilled in theart.

Typically the photochromic material is present in a photochromic amount;that is, in an amount yielding a color change distinguishable by thenaked eye upon exposure to radiation. The amount of photochromicmaterial incorporated into the outer layer (b) or into the compositionused to form the outer layer (b) may range from 0.5 to 40 weight percentbased on the weight of the solids in composition. The amount ofphotochromic material may range from 1 to 30 weight percent, from 3 to20 weight percent, or from 3 to 10 weight percent. The amount ofphotochromic material present in the outer layer (b) may range betweenany combination of these values, inclusive of the recited range.

In addition to or in lieu of the photochromic material, the outer layer(b) can include one or more static dyes (also referred to as “fixedtint” dyes). Such static dyes generally are compatible (chemically andcolor-wise) with the photochromic materials if used in combination. Forexample, the dye may be selected to complement the color resulting fromactivated photochromic materials, e.g., to achieve a more neutral coloror absorb a particular wavelength of incident light. In anotherembodiment, the dye may be selected to provide a desired hue to theoptical article when the photochromic materials are in an unactivatedstate.

Suitable static dyes can include, for example, azo dyes, anthraquinonedyes, xanthenes dyes, azime dyes and mixtures thereof.

In a further embodiment, the optical article of the present inventioncan further comprise a polarizer disposed between the base layer (a) andthe outer layer (b). Suitable polarizers may comprise a variety ofdifferent constructions and materials. Such constructions can includefree-standing or non-laminated polarized films, such as poly(vinylalcohol) (“PVA”) polarized films, films with removable protectivesheeting, and films with outer permanent protective coatingsorsupportive plastic layers, i.e., “wafers” (e.g.,polycarbonate/PVA/polycarbonate construction). Such polarizers aredescribed in U.S. Pat. No. 7,002,744 at column 5, line 20 to column 6,line 17, the cited portions of which are incorporated herein byreference. Additionally, in such an embodiment, the polarizer may beformed from a polarizing coating or series of coatings which have beenapplied to the surface of the base layer prior to casting the outerlayer (b) over the base layer (a).

The optical article of the present invention may further comprise an atleast partial film or coating superposed over the outer layer (b). Sucha coating or film may comprise, inter alia, a photochromic coating, tintcoating, polarizing coating, and/or an abrasion resistant or otherprotective coating.

The types of material used for the film or coating may vary widely andbe chosen from the polymeric organic materials of the substrate and theprotective films described hereinafter. Moreover, the film or coatingmay comprise the previously mentioned reaction products comprisingthioether functional, oligomeric polythiols. The thickness of the filmsof polymeric organic materials may vary widely. The thickness may range,for example, from 0.1 mil to 40 mils and any range of thicknessesbetween these values, inclusive of the recited values. However, ifdesired, greater thicknesses may be used.

The polymeric organic materials may be chosen from thermosettingmaterials, thermoplastic materials and mixtures thereof. Examples offilms of polymeric organic materials are disclosed in U.S. PatentPublication 2004/0096666 in paragraphs [0082] to [0098] which disclosureof such polymeric films is incorporated herein by reference.

In certain embodiments, the film or coating comprises thermoplasticpolymeric organic materials such as nylon, poly(vinyl acetate), vinylchloride-vinyl acetate copolymer, poly (C₁-C₈ alkyl)acrylates, poly(C₁-C₈ alkyl)methacrylates, styrene-butadiene copolymer resin,poly(urea-urethanes), polyurethanes, polyterephthalates, polycarbonates,polycarbonate-silicone copolymer and mixtures thereof.

Often, a protective film can be applied to the article surface e.g., toprevent scratches from the effects of friction and abrasion. Theprotective film connected to the optical article of the presentinvention is typically an at least partially abrasion resistant film.The phrase “an at least partially abrasion resistant film” refers to anat least partial film of an at least partially cured coating or sheet ofa protective polymeric material that demonstrates a resistance toabrasion that is greater than the standard reference material, typicallya plastic made of CR-39® monomer available from PPG Industries, Inc, astested in a method comparable to ASTM F-735 Standard Test Method forAbrasion Resistance of Transparent Plastics and Coatings Using theOscillating Sand Method.

The protective film may be chosen from protective sheet materials,protective gradient films (which also provide a gradient in hardness forthe films between which they are interposed), protective coatings andcombinations thereof. Protective coatings such as hardcoats may beapplied onto the surface of the polymeric film, the substrate and/or anyapplied films, e.g., superjacent to protective transitional films.

When the protective film is chosen from protective sheet materials, itmay be chosen, for example, from the protective polymeric sheetmaterials disclosed in paragraphs [0118] to [0126] of U.S. PatentPublication 2004/0096666, incorporated herein, by reference. Also theprotective film can comprise film or sheet materials comprising the anyof the previously mentioned reaction products comprising any of thethioether functional, oligomeric polythiols of the present invention.

The protective gradient films provide an at least partially abrasionresistant film and may be subsequently coated with another protectivefilm. The protective gradient film may serve to protect the articleduring shipping or subsequent handling prior to the application of theadditional protective film. After application of an additionalprotective film, the protective gradient film provides a gradient inhardness from one applied film to another. The hardness of such filmsmay be determined by methods known to those skilled in the art. Theprotective film may also be superjacent to a protective gradient film.Non-limiting examples of protective films providing such gradientproperties include the radiation cured (meth)acrylate-based coatingsdescribed in U.S. Patent Application Publication 2003/0165686 inparagraphs to [0023] and [0079] to [0173], incorporated herein byreference.

The protective films may also include protective coatings. Examples ofprotective coatings known in the art that provide abrasion and scratchresistance are chosen from polyfunctional acrylic hard coatings,melamine-based hard coatings, urethane-based hard coatings, alkyd-basedcoatings and organosilane type coatings. Non-limiting examples of suchabrasion resistant coatings are disclosed in U.S. Patent Application2004/0096666 in paragraphs [0128] to [0149], and in U.S. PatentApplication 2004/0207809 in paragraphs [0205] to [0249], bothdisclosures incorporated herein by reference.

The optical article of the present invention may optionally furthercomprise an at least partially polarizing surface treatment, coating, orfilm to the surface of the outer layer (b). The phrase “at leastpartially polarizing” means that from some to all of the vibrations ofthe electric field vector of lightwaves is confined to one direction orplane by the surface treatment. Such polarizing effects may be achievedby applying to the optical element a film having an aligned dichroicmaterial to at least partially polarize transmitted radiation. In onenon-limiting embodiment, a polymeric sheet is stretched to align thedichroic material applied to the polymeric sheet. In anothernon-limiting embodiment, a coating is cured in a directional fashion,e.g., using polarized ultraviolet radiation, to align the dichroicmaterials in the coating.

The optical article may further comprise an at least partiallyantireflective surface treatment. The phrase “an at least partiallyantireflective surface” treatment means that there is an at leastpartial improvement in the antireflective nature of the optical elementto which it is applied. In non-limiting embodiments, there may be areduction in the amount of glare reflected by the surface of the treatedoptical element and/or an increase in the percent transmittance throughthe treated optical element as compared to an untreated optical element.

In other non-limiting embodiments, an at least partially antireflectivesurface treatment, e.g., a monolayer or multilayer of metal oxides,metal fluorides, or other such materials, can be connected to thesurface of the optical article, e.g., lenses, of the present inventionthrough vacuum evaporation, sputtering, or some other method.

The optical article of the present invention may further comprise an atleast partially hydrophobic surface treatment. The phrase “an at leastpartially hydrophobic, surface” is a film that at least partiallyimproves the water repellent nature of the substrate to which it isapplied by reducing the amount of water from the surface that can adhereto the substrate as compared to an untreated substrate.

When the optical article is a lens, the mixture of reactants can beintroduced into a mold and the mold can be heated using a variety ofconventional techniques known in the art. The thermal cure cycle canvary depending on, for example, the reactivity and molar ratio of thereactants and the presence of catalyst(s). In one example, the thermalcure cycle can include heating the reactants from room temperature to200° C. over a period of from 0.5 hours to 72 hours.

The present invention is more particularly described in the followingexamples that are intended as illustration only, since numerousmodifications and variations therein will be apparent to those skilledin the art, without departing from the spirit and scope of theinvention.

EXAMPLES Compositions Used to Prepare Base Layer (a)

In the following examples, unless otherwise stated, the refractive indexreported as D-line (nD) and/or E-line (nE) and Abbe number were measuredon a multiple wavelength Abbe Refractometer Model DR-M2 manufactured byATAGO Co., Ltd.; the refractive index and Abbe number of liquids weremeasured in accordance with ASTM-D1218; the refractive index and Abbenumber of solids was measured in accordance with ASTM-D-542.

The viscosity was measured using a Brookfield CAP 2000+ Viscometer.

Hardness was measured in accordance with ISO standard test method BS ENISO 14577-1:2002, using a Fischer Scope H-100 instrument, supplied byFischer Technology, Inc., and was reported as Martens Hardness (HM0.3/15/0), in the units of Newtons (N)/mm². As required in said standardtest method, the following test parameters were specified: Maximum TotalLoad applied to sample was 0.3 Newtons (N), time period over whichMaximum Total Load was applied to sample was 15 seconds, and the time ofduration for which said Maximum Total Load was then applied to samplewas 0 seconds. Therefore, the test results were designated with the term“HM 0.3/15/0” in order to reflect these three test parameters.

Impact testing was accomplished in accordance with the Impact EnergyTest, as described herein, and the results are reported in energy units(Joules). The Impact Energy Test consists of testing a flat sheet sampleof polymerizate having a thickness of 3 mm, and cut into a square pieceapproximately 4 cm×4 cm. Said flat sheet sample of polymerizate issupported on a flat O-ring which is attached to top of the pedestal of asteel holder, as defined below. Said O-ring is constructed of neoprenehaving a hardness of 40±5 Shore A durometer, a minimum tensile strengthof 8.3 MPa, and a minimum ultimate elongation of 400 percent, and has aninner diameter of 25 mm, an outer diameter of 31 mm, and a thickness of2.3 mm. Said steel holder consists of a steel base, with a mass ofapproximately 12 kg, and a steel pedestal affixed to said steel base.The shape of said steel pedestal is approximated by the solid shapewhich would result from adjoining onto the top of a cylinder, having anouter diameter of 75 mm and a height of 10 mm, the frustum of a rightcircular cone, having a bottom diameter of 75 mm, a top diameter of 25mm, and a height of 8 mm, wherein the center of said frustum coincideswith the center of said cylinder. The bottom of said steel pedestal isaffixed to said steel base, and the neoprene O-ring is centered andaffixed to the top of the steel pedestal. The flat sheet sample ofpolymerizate is centered and set on top of the O-ring. The Impact EnergyTest is carried out by dropping steel balls of increasing weight from adistance of 60 inches (1.27 meters) onto the center of the flat sheetsample. The sheet is determined to have passed the test if the sheetdoes not fracture. The sheet is determined to have failed the test whenthe sheet fractures. As used herein, the term “fracture” refers to acrack through the entire thickness of the sheet into two or moreseparate pieces, or detachment of one or more pieces of material fromthe backside of the sheet (i.e., the side of the sheet opposite the sideof impact). The impact strength of the sheet is reported as the impactenergy that corresponds to the highest level (i.e., largest ball) atwhich the sheet passes the test, and it is calculated according to thefollowing formula:

E=mgd

wherein E represent impact energy in Joules (J), m represents mass ofthe ball in kilograms (kg), g represents acceleration due to gravity(i.e., 9.80665 m/sec²) and d represents the distance of the ball drop inmeters (i.e., 1.27 m).

The NCO concentration of the prepolymer (Component A) was determined byreaction with an excess of n-dibutylamine (DBA) to form thecorresponding urea followed by titration of the unreacted DBA with HClin accordance with the following procedure.

Reagents

-   -   1. Tetrahydrofuran (THF), reagent grade.    -   2. 80/20 THF/propylene glycol (PG) mix.        -   This solution was prepared in-lab by mixing 800 mls PG with            3.2 liters of THF in a 4-liter bottle.    -   3. DBA, dibutylamine certified ACS.    -   4. DBA/THF solution. 150 mL of DBA was combined with 750 mL of        THF; it was mixed well and transferred to an amber bottle.    -   5. Hydrochloric acid, concentrated. ACS certified.    -   6. Isopropanol, technical grade.    -   7. Alcoholic hydrochloric acid, 0.2N. 75 ml of conc. HCl was        slowly added to a 4-liter bottle of technical grade isopropanol        while stirring with a magnetic stirrer; it was mixed for a        minimum of 30 minutes. This solution was standardized using THAM        (Tris hydroxylmethyl amino methane) as follows: Into a glass        100-mL beaker, was weighed approximately 0.6 g (HOCH₂)₃CNH₂        primary standard to the nearest 0.1 mg and the weight was        recorded. 100 mL DI water was added and mixed to dissolve and        titrated with the prepared alcoholic HCl.        -   This procedure was repeated a minimum of one time and the            values were averaged using the calculation below.

${{Normality}\mspace{11mu} {HCL}} = \frac{\left( {{{Standard}\mspace{14mu} {{wt}.}},{grams}} \right)}{\left( {{mLs}\mspace{14mu} {HCl}} \right)\mspace{11mu} (0.12114)}$

Equipment

-   -   1. Polyethylene beakers, 200-mL, Falcon specimen beakers, No.        354020.    -   2. Polyethylene lids for above, Falcon No. 354017.    -   3. Magnetic stirrer and stirring bars.    -   4. Brinkmann dosimeter for dispensing or 10-mL pipette.    -   5. Autotitrator equipped with pH electrode.    -   6. 25-mL, 50-mL dispensers for solvents or 25-mL and 50-mL        pipettes.

Procedure

-   -   1. Blank determination: Into a 220-mL polyethylene beaker was        added 50 mL THF followed by 10.0 mL DBA/THF solution.        -   The solution was capped and mixed with magnetic stirring for            5 minutes. 50 mL of the 80/20 THF/PG mix was added and            titrated using the standardized alcoholic HC1 solution and            this volume was recorded. This procedure was repeated and            these values averaged for use as the blank value.    -   2. In a polyethylene beaker was weighed 1.0 gram of prepolymer        sample and the weight was recorded to the nearest 0.1 mg. 50 mL        THF was added, the sample was capped and allowed to dissolve        with magnetic stirring.    -   3. 10.0 mL DBA/THF solution was added, the sample was capped and        allowed to react with stirring for 15 minutes.    -   4. 50 mL of 80/20 THF/PG solution was added.    -   5. The beaker was placed on the titrator and the titration was        started. This procedure was repeated.

Calculations

${\% \mspace{14mu} {NCO}} = \frac{\left( {{{mls}\mspace{14mu} {Blank}} - {{mls}\mspace{14mu} {Sample}}} \right) \times \left( {{Normality}\mspace{14mu} {HC}\; 1} \right) \times (4.2018)}{{{Sample}\mspace{14mu} {weight}},g}$${IEW} = \frac{\left( {{{Sample}\mspace{14mu} {{wt}.}},{grams}} \right) \times (1000)}{\left( {{{mls}\mspace{14mu} {Blank}} - {{mls}\mspace{14mu} {Sample}}} \right) \times \left( {{Normality}\mspace{14mu} {HC}\; 1} \right)}$

IEW=Isocyanate Equivalent Weight

The SH groups within the product were determined using the followingprocedure. A sample size (0.1 mg) of the product was combined with 50 mLof tetrahydrofuran (THF)/propylene glycol (80/20) and stirred at roomtemperature until the sample was substantially dissolved. Whilestirring, 25.0 mL of 0.1 N iodine solution (which was commerciallyobtained from Aldrich 31, 8898-1) was added to the mixture and thenallowed to react for a time period of from 5 to 10 minutes. To thismixture was added 2.0 mL concentrated HC1. The mixture was then titratedpotentiometrically with 0.1 N sodium thiosulfate in the millivolt (mV)mode. A blank value was initially obtained by titrating 25.0 mL iodine(including 1 mL of concentrated hydrochloric acid) with sodiumthiosulfate in the same manner as conducted with the product sample.

${\% \mspace{14mu} {SH}} = \frac{\left( {{{mls}\mspace{14mu} {Blank}} - {{mls}\mspace{14mu} {Sample}}} \right) \times \left( {{Normality}\mspace{14mu} {NA}_{2}S_{2}O_{3}} \right) \times (3.307)}{{{Sample}\mspace{14mu} {weight}},g}$

Example 1 Synthesis of 2/1 (mol/mol) adduct of Dimercaptodiethylsulfide(DMDS) and Propargyl Alcohol (PA)

In a glass jar with magnetic stirrer were mixed Dimercaptodiethylsulfidefrom Nisso Maruzen, Japan, 154.0 g., 1.0 mol and Propargyl alcohol (PA)from Aldrich, 28.0 g., 0.5 mols at room temperature. Then this mixturewas heated up to 60° C. using an oil bath. The mixture was kept at thistemperature upon stirring for 30 min. An exothermic reaction started totake place leading to increase in the temperature of the reactionmixture up to 80° C. for a short period of time. This exothermicreaction was over after 30 minutes and the reaction temperature wentdown to 60° C., the temperature of the heating bath. Radical initiatorVazo 64, 50 mg., 275 ppm was added three times at intervals of 5 hourswhile the mixture was stirred at 60° C. Then equivalent weight of 181.5g/equiv (theoretical 182 g/equiv) was measured, based on that Mn=363 wascalculated (theoretically expected 364). Vazo 64, 50 mg., 275 ppm wasadded again and the mixture was heated at 60° C. upon stirring foranother 5 hours. The equivalent weight measurement showed no changes andthe reaction was considered completed. The viscosity of thus obtainedclear water white product was 258 cP (25° C.), nD=1.627, Abbe 36,nE=1.631, Abbe 36.

Example 2 Synthesis of 3/2 (mol/mol) Adduct of Dimercaptodiethylsulfide(DMDS) and Propargyl Alcohol

In a glass jar with magnetic stirrer were mixed DMDS from Nisso Maruzen,Japan, 346.5 g., 2.25 mol and Propargyl alcohol from Aldrich, 84.0 g.,1.5 mols at room temperature. Then this mixture was heated up to 50° C.using an oil bath. The mixture was kept at this temperature uponstirring for 1.5 hours. An exothermic reaction started to take placeleading to increase in the temperature of the reaction mixture up to 70°C. for a short period of time, then the temperature went down to 50° C.,the temperature of the heating bath. Radical initiator Vazo 52, 120 mg,275 ppm was added twice at 15 hours interval and the mixture was stirredat 50° C. Then SH equivalent weight was measured, it was 214. Vazo 52,120 mg., 275 ppm was added again and the mixture was heated at 55° C.upon stirring for another 15 hours. The equivalent weight of 283 g/equiv(theoretical 287 g/equiv) was measured. The viscosity of thus obtainedclear water white viscous product was 115 cP (73° C.), nD=1.631, Abbe38, nE=1.635, Abbe 38.

Example 3 Synthesis of 2/1 (mol/mol) Adduct of Dimercaptodiethylsulfide(DMDS) and Phenyl Acetylene (PHA)

In a glass jar with magnetic stirrer were mixed DMDS from Nisso Maruzen,Japan, 77.0 g., 0.5 mol and Phenyl acetylene from Aldrich, 25.5 g., 0.25mols at room temperature. Then this mixture was heated up to 70° C.using an oil bath. Vazo 64, 20 mg, 200 ppm was added four times at 15hours interval and the mixture was stirred at 70° C. Then SH equivalentweight was measured, it was 173 g/equiv. Vazo 64, 20 mg., 200 ppm wasadded again and the mixture was heated at 70° C. upon stirring foranother 15 hours. The SH equivalent weight of 173 g/equiv (theoretical205 g/equiv) was measured. The product obtained was transparent; yellowviscous liquid, nD=1.635, Abbe 26, nE=1.641, Abbe 26.

Example 4 Synthesis of 2/1 (mol/mol) Adduct of Dimercaptodiethylsulfide(DMDS) and 1,3-Diisopropenyl Benzene (DIPEB)

524.6 g DMDS (3.4 moles) was charged to a glass jar, and the content washeated to 60° C. To the jar was slowly added 269.0 g DIPEB (1.7 moles)with mixing. Once the addition of DIPEB was completed, the jar wasplaced in an oven heated to 60° C. for 2 hours. Afterwards, 0.1 g VAZO52 was dissolved into the contents of the jar, and the jar was returnedto the oven. After 20 hours, the resulting sample was titrated for —SHequivalents and was found to have an equivalent weight of 145 g/mol. 0.1g VAZO 52 was dissolved into the reaction mixture, which was thenreturned to the oven. Over the course of 8 hours, two additions of 0.2 gVAZO 52 were made, and the reaction mixture kept in the 60° C. oven overthat time frame. 17 hours after the final addition of VAZO 52 was made,the resulting sample was titrated to an equivalent weight of 238 g/equiv(theoretical 233 g/equivalent). The viscosity of the material at 25° C.was measured and found to be 490 cps. The product obtained wastransparent liquid, n_(D)=1.611, Abbe 35, nE=1.615, Abbe 35.

Example 5 Synthesis of 2/1 (mol/mol) Adduct of Dimercaptodiethylsulfide(DMDS) and 5-Vinyl-2-norbornene (VNB)

77 g DMDS (0.5 moles) was charged to a glass jar, and the content washeated to 60° C. To this jar was slowly added 30 g VNB (0.25 moles) withmixing, while keeping the temperature of the mixture ˜60° C. Aftercompletion of the addition the mixture was heated at 60° C. for another30 min, then 0.2 g VAZO 67 was dissolved into the contents of the jar,and the jar was heated at 65° C. for 20 hours. The resulting product wasanalyzed for SH content by titration with Iodine as describedpreviously. SH equivalent weight of 216 g/equiv (theoretical 214g/equivalent) was found. The viscosity of the material at 25° C. wasmeasured and found to be 460 cps. The product obtained was transparentcolorless liquid, nD=1.607, Abbe 39, nE=1.610, Abbe 39. The yield wasquantitative.

Example 6 One Pot Synthesis of Oligomeric Polythiol, Adduct ofDimercaptodiethylsulfide (DMDS), 1,3-Diisopropenyl benzene (DIPEB), andPropargyl Alcohol (PA)

127.6 g DMDS (0.828 moles), 65.5 g DIPEB (0.415 moles) and 6.8 g PA(0.121 moles) were charged to a glass jar. The mixture was stirred atroom temperature for 30 min. After that the mixture was heated at 60° C.for another 30 min, then 0.1 g VAZO 67 was dissolved into the contentsof the jar, and the jar was heated at 65° C. for 15 hours. Twoadditional portions of 0.100 g VAZO 67 were added in an interval of 6hours. The resulting product was analyzed for SH content by titrationwith Iodine as described previously. SH equivalent weight of 335 g/equiv(theoretical 341 g/equivalent) was found. The viscosity of the materialat 73° C. was measured and found to be 150 cps. The product obtained wastransparent colorless liquid, nD=1.6152, Abbe 37, nE=1.620, Abbe 36.

Example 7 Synthesis of 2/1 (mol/mol) Adduct of the Product of Example 4and Propargyl Alcohol5

The product of Example 4, 200.0 g., 0.42 mol and propargyl alcohol, 11.6g., 0.21 mol were mixed at room temperature. Then this mixture washeated up to 65° C. Radical initiator Vazo 52, 42 mg, 200 ppm was addedthree times at intervals of 5 hours while the mixture was stirred at 65°C. Then SH equivalent weight was measured, it was 499 g/equiv. Themixture was heated at 65° C. for another 5 hours and SH equivalentweight was measured again, it was 499 g/equiv, based on that Mn=998 wascalculated (theoretically expected 1008). The viscosity of thus obtainedclear water white oligomeric mixture was 463 cP (73° C.), nD=1.620, Abbe36, nE=1.624, Abbe 35.

Example 8 Synthesis of 2/0.32/0.68 (mol/mol/mol) Adduct of the Productof Example 4, Propargyl Alcohol and 5-Vinyl-2-norbornene (VNB)

The product of Example 4, 238.0 g., 0.5 mol, propargyl alcohol, 4.48 g.,0.08 mol and 5-vinyl-2-norbornene, 20.4 g., 0.17 mol were mixed at roomtemperature. Then this mixture was heated up to 60° C. until it becamehomogeneous. Radical initiator Vazo 52, 20 mg, 76 ppm was added threetimes at intervals of 5 hours while the mixture was stirred at 60° C.Then SH equivalent weight was measured, it was 511 g/equiv, based onthat Mn=1022 was calculated (theoretically expected 1051). Theequivalent weight did not change after another 5 hours of heating at 60°C. and stirring. The viscosity of thus obtained clear water whiteoligomeric mixture was 468 cP (73° C.), nD=1.615, Abbe 37, nE=1.619,Abbe 36.

Example 9 Synthesis of 2/0.5/0.5 (mol/mol/mol) Adduct of the Product ofExample 4, Propargyl Alcohol and 1,3-Diisopropenyl benzene (DIPEB)

The product of Example 4, 238.0 g., 0.5 mol, propargyl alcohol, 7.0 g.,0.125 mol and 1,3-Diisopropenyl benzene, 19.75 g, 0.125 mol were mixedat room temperature. Then this mixture was heated up to 65° C. until itbecame homogeneous. Radical initiator Vazo 52, 20 mg, 76 ppm was addedthree times at intervals of 5 hours while the mixture was stirred at 65°C. Then SH equivalent weight was measured, it was 510 g/equiv, based onthat M_(n)=1020 was calculated (theoretically expected 1059). Theequivalent weight did not change after another 5 hours of heating at 60°C. and stirring. The viscosity of thus obtained clear water whiteoligomeric mixture was 452 cP (73° C.), nD=1.617, Abbe 36, nE=1.621,Abbe 35.

Example 10 Synthesis of Polythiourethane Prepolymer Using the Product ofExample 7

4,4-Dicyclohexylmethane diisocyanate (Desmodur W) from Bayer Corp.(135.0 g, 1.03 mole eq.) the product of Example 7 (70.0 g, 0.2102 moleeq.) were mixed and degassed under vacuum for 2.5 hours at roomtemperature. The mixture was flushed with Nitrogen and heated for 18hours at a temperature of 120° C. SH group analysis showed completeconsumption of SH groups. The heating was terminated. The resultingclear mixture had viscosity (73° C.) of 928 cP, nE of 1.551 (20° C.),Abbe number of 45; and NCO groups of 16.73%.

Example 11 Synthesis of Polythiourethane Prepolymer Using the Product ofExample 8

4,4-Dicyclohexylmethane diisocyanate (Desmodur W) from Bayer Corp.(115.4 g, 0.881 mole eq.), isophorone diisocyanate (IPDI) from BayerCorp. (12.8 g, 0.115 mole eq.) and the product of Example 8 (100.0 g,0.226 mole eq.) were mixed and degassed under vacuum for 2.5 hours atroom temperature. N,N-dimethylcyclohexyl amine (0.06 g, 263 ppm) wasadded to the mixture. The mixture was flushed with Nitrogen and heatedfor 5 hour at a temperature of 65° C. SH group analysis after thatshowed complete consumption of SH groups. The heating was terminated.The resulting clear mixture had viscosity (73° C.) of 1403 cP, nE of1.561 (20° C.), Abbe number of 43; and NCO groups of 13.36%.

Example 12 Synthesis of Polythiourethane Prepolymer Using the Product ofExample 9

4,4-Dicyclohexylmethane diisocyanate (Desmodur W) from Bayer Corp.(126.5 g, 0.965 mole eq.), isophorone diisocyanate (IPDI) from BayerCorp. (14:1 g, 0.127 mole eq.) and the product of Example 9 (100.0 g,0.245 mole eq.) were mixed and degassed under vacuum for 2.5 hours atroom temperature. N,N-dimethylcyclohexyl amine (0.075 g, 312 ppm) wasadded to the mixture. The mixture was flushed with Nitrogen and heatedfor 5 hour at a temperature of 65° C. SH group analysis after thatshowed complete consumption of SH groups. The heating was terminated.The resulting clear mixture had viscosity (73° C.) of 1320 cP, nE of1.558 (20° C.), Abbe number of 44; and NCO groups of 14.99%.

Example 13 Chain Extension of the polythiourethane Prepolymer of Example10

The product of Example 10 (50 g) was degassed under vacuum at atemperature of 60° C. for four hours. Diethyltoluenediamine (Commercialname is Ethacure 100 from Albemarle Corporation) (DETDA) (9.76 g), theproduct of Example 4 (19.28 g) and N,N-dimethylcyclohexyl amine (0.030g) were mixed and degassed under vacuum at a temperature of 60° C. for 2hours. The two mixtures were then mixed together at the same temperatureand charged between a preheated glass plates mold. The material wascured in a preheated oven at a temperature of 110° C. for 72 hours. Thecured material was clear and had nE of 1.595 (20° C.) and Abbe number of38 and Martens Hardness 110.

Example 14 Chain Extension of the Prepolymer of Example 11

The product of Example 11 (40 g) was degassed under vacuum at atemperature of 60° C. for four hours. Diethyltoluenediamine (Commercialname is Ethacure 100 from Albemarle Corporation) (DETDA) (6.79 g) andthe product of Example 4 (10.77 g) were mixed and degassed under vacuumat a temperature of 60° C. for 2 hours. The two mixtures were then mixedtogether at the same temperature and charged between a preheated glassplates mold. The material was cured in a preheated oven at a temperatureof 110° C. for 72 hours. The cured material was clear and had nE of1.596 (20° C.) and Abbe number of 38 and Martens Hardness 84.

Example 15 Chain Extension of the Prepolymer of Example 12

The product of Example 12 (40 g) was degassed under vacuum at atemperature of 60° C. for four hours. Diethyltoluenediamine (Commercialname is Ethacure 100 from Albemarle Corporation) (DETDA) (7.63 g) andthe product of Example 4 (12.04 g) were mixed and degassed under vacuumat a temperature of 60° C. for 2 hours. The two mixtures were then mixedtogether at the same temperature and charged between a preheated glassplates mold. The material was cured in a preheated oven at a temperatureof 120° C. for 24 hours. The cured material was clear and had nE of1.596 (20° C.) and Abbe number of 38 and Martens Hardness 97.

Example 16 One Pot Synthesis of Polyurethane Polymer Using the Productof Example 1

The product of Example 1 (27.8 g) was degassed under vacuum at atemperature of 60° C. for four hours. 4,4-dicyclohexylmethanediisocyanate (Desmodur W) from Bayer (30.0 g) and N,N-dimethylcyclohexylamine (0.020 g) were mixed well, then the mixture was degassed undervacuum at a temperature of 60° C. for 2 hours. The two mixtures werethen mixed together at the same temperature and charged between apreheated glass plates mold. The material was cured in a preheated ovenat a temperature of 125° C. for 24 hours. The cured material was clearand had refractive index (e-line) of 1.595 (20° C.) and Abbe number of41 and Martens hardness 109.

Example 17 One Pot Synthesis of Polyurethane/Urea Polymer Using theProduct of Example 2

Diethyltoluenediamine from Albemarle Corporation (DETDA) (1.7 g) and theproduct of Example 2 (24.6 g) were mixed and degassed under vacuum at atemperature of 75° C. for four hours. 4,4-dicyclohexylmethanediisocyanate (Desmodur W) from Bayer (25.0 g) and N,N-dimethylcyclohexylamine (0.020 g) were mixed well, then the mixture was degassed undervacuum at a temperature of 60° C. for 2 hours. The two mixtures werethen mixed together and charged between a preheated glass plates mold.The material was cured in a preheated oven at a temperature of 120° C.for 48 hours. The cured material was clear and had nE of 1.593 (20° C.)and Abbe number of 40 and Martens Hardness 112.

Example 18 One Pot Synthesis of Polyurethane Polymer Using the Productof Example 1

The product of Example 1 (29.7 g) was degassed under vacuum at atemperature of 75° C. for four hours. 4,4-dicyclohexylmethanediisocyanate (Desmodur W) from Bayer (30.0 g),1,3-bis(1-isocyanato-1-methylethyl)-benzene) from Cytec Industries Inc(TMXDI) (3.02 g) and N,N-dimethylcyclohexyl amine (0.020 g) were mixedwell, then the mixture was degassed under vacuum at a temperature of 60°C. for 2 hours. The two mixtures were then mixed together and chargedbetween a preheated glass plates mold. The material was cured in apreheated oven at a temperature of 125° C. for 48 hours. The curedmaterial was clear, yellowish and had nE of 1.596 (20° C.) and Abbenumber of 41 and Martens hardness 123.

Example 19 One Pot Synthesis of Polyurethane Polymer Using the Productof Example 1

The product of Example 1 (22.90 g) was degassed under vacuum at atemperature of 75° C. for four hours. Isophorone diisocyanate (IPDI)from Bayer (21.18 g) and N,N-dimethylcyclohexyl amine (0.020 g) weremixed well, then the mixture was degassed under vacuum at a temperatureof 60° C. for 2 hours. The two mixtures were then mixed together andcharged between a preheated glass plates mold. The material was cured ina preheated oven at a temperature of 125° C. for 24 hours. The curedmaterial was clear and had nE of 1.595 (20° C.) and Abbe number of 40and Martens Hardness 141.

Example 20 One Pot Synthesis of Polyurethane Polymer Using the Productof Example 1

The product of Example 1 (30.95 g) was degassed under vacuum at atemperature of 75° C. for four hours. Isophorone diisocyanate (IPDI)from Bayer (15.00 g), 4,4-dicyclohexylmethane diisocyanate (Desmodur W)from Bayer (15.0 g) and N,N-dimethylcyclohexyl amine (0.020 g) weremixed well, then the mixture was degassed under vacuum at a temperatureof 60° C. for 2 hours. The two mixtures were then mixed together andcharged between a preheated glass plates mold. The material was cured ina preheated oven at a temperature of 125° C. for 24 hours. The curedmaterial was clear and had nE of 1.595 (20° C.) and Abbe number of 40and Martens hardness 127.

Example 21 One Pot Synthesis of Polyurethane/Urea Polymer Using theProduct of Examples 2 and 4

The product of Example 2 (9.75 g) was mixed with the product of Example4 (19.0 g) and diethyltoluenediamine from Albemarle Corporation (DETDA)(7.92 g). The mixture was degassed under vacuum at a temperature of 75°C. for four hours. 4,4-dicyclohexylmethane diisocyanate (Desmodur W)from Bayer (30.0 g) and N,N-dimethylcyclohexyl amine (0.020 g) weremixed well, then the mixture was degassed under vacuum at a temperatureof 60° C. for 2 hours. The two mixtures were then mixed together andcharged between a preheated glass plates mold. The material was cured ina preheated oven at a temperature of 125° C. for 24 hours. The curedmaterial was clear and had nE of 1.592 (20° C.) and Abbe number of 39and Martens Hardness 125.

Example 22 One Pot Synthesis of Polyurethane/Urea Polymer Using theProduct of Example 6

The product of Example 6 (36.7 g) was degassed under vacuum at atemperature of 60° C. for four hours. 4,4-Dicyclohexylmethanediisocyanate (Desmodur W) from Bayer (33.3 g) and N,N-dimethylcyclohexylamine (0.020 g) were mixed well, then the mixture was degassed undervacuum at a temperature of 60° C. for two hours. Diethyltoluenediaminefrom Albemarle Corporation (DETDA) (9.73 g) was degassed under vacuum atroom temperature for two hours. The three mixtures were then mixedtogether and charged between a preheated glass plates mold. The materialwas cured in a preheated oven at a temperature of 110° C. for 24 hours.The cured material was clear and had nE of 1.595 (20° C.) and Abbenumber of 38 and Martens hardness 109.

Example 23 One Pot Synthesis of Polyurethane/Urea Polymer Based on theProduct Described in Example 4, Example 7, DETDA and Desmodur W

The components listed in Table 1 were used in the amounts indicated toprepare polymeric sheets having a thickness of 3.5 mm for which testresults are reported in Table 2. The polymeric sheets were preparedusing a mixture of 3 components injected into a specially designedmolding machine from Max Machinery. The first component was Desmodur W.The second component was combination of the catalyst,N,N-dimethylcyclohexyl amine with products of Example 4 and Example 7.The first component was degassed under vacuum at room temperature for 16hours. The second component was degassed under vacuum at 44° C. for 16hours prior to use. The third component was DETDA obtained fromAlbemarle Corporation, this component was degassed under vacuum at roomtemperature for 16 hours prior to use. The molding machine was aUrethane Processor Model No. 601-000-232, which was obtained from MaxMachinery in Healdsburg, Calif., USA. The blended mixture was theninjected into a preheated glass plate mold that was treated with anexternal mold release agent. The molds were placed in a convection ovenfor 24 hours at a temperature of 110° C. Afterwards, the temperature wasramped down to 85° C. before demolding. The resulting sheets were cutinto sizes appropriate for the testing described hereinbefore andreported in Table 2.

TABLE 1 Example EX. 4 EX. 7 Catalyst Desmodur DETDA # (Equiv) (Equiv)(ppm) W (equiv) (Equiv) 23 0.25 0.27 300 1 0.43

TABLE 2 Martens Example Hardness nE Density # N/mm² (20° C.) AbbeGram/cm³ 23 112 1.5957 37.6 1.17

Examples 24A-O Polyurethane and Polyureaurethane Formulations Based onProducts Described in Examples 1 and 5, DMDS, DETDA and Desmodur W

The components listed in Table 3 were used in the amounts indicated toprepare polymeric sheets having a thickness of 3.5 mm for which testresults are reported in Table 4. The polymeric sheets were preparedusing a mixture of 3 components injected into a specially designedmolding machine from Max Machinery described in Example 23. The firstcomponent was Desmodur W. The second component was combination of thecatalyst, N,N-dimethylcyclohexyl amine with dithiols of Examples 1, 5and/or DMDS. Each of these components was degassed under vacuum at 50°C. for 16 hours prior to use. The third component was DETDA obtainedfrom Albemarle Corporation, this component was degassed under vacuum atroom temperature for 16 hours prior to use. The blended mixture was theninjected into a preheated glass plate mold that was treated with anexternal mold release agent. The molds were placed in a convection ovenfor 24 hours at a temperature of 110° C. Afterwards, the temperature wasramped down to 85° C. before demolding. The resulting sheets were cutinto sizes appropriate for the testing described hereinbefore andreported in Table 4.

TABLE 3 DMDS EX. 1 EX. 5 Catalyst Desmodur DETDA Example # (Equiv)(Equiv) (Equiv) (ppm) W (equiv) (Equiv) 23A 0 1.00 0 300 1 0 23B 0 0.700.30 300 1 0 23C 0 0.40 0.30 300 1 0.30 23D 0.40 0.40 0 300 1 0.20 23E0.40 0.40 0.20 300 1 0 23F 0 0.70 0 300 1 0.30 23G 0.20 0.56 0.12 300 10.12 23H 0.18 0.40 0.30 300 1 0.12 23I 0.21 0.40 0.09 300 1 0.30 23J0.30 0.40 0.30 300 1 0 23K 0.30 0.40 0 300 1 0.30 23L 0 0.40 0.30 300 10.30 23M 0 0.70 0 300 1 0.30 23N 0 0.70 0.30 300 1 0 23O 0.40 0.60 0 3001 0

TABLE 4 Martens Example Hardness nE Density # N/mm² (20° C.) AbbeGram/cm³ 23A 106 1.5988 41.6 1.23 23B 105 1.6008 41.1. 1.22 23C 1241.5902 40.8 1.19 23D 121 1.5868 40.6 1.20 23E 108 1.5987 40.7 1.22 23F122 1.5859 40.8 1.19 23G 115 1.5943 40.5 1.21 23H 116 1.5957 40.7 1.2123I 123 1.5843 40.4 1.19 23J 107 1.5991 40.6 1.22 23K 124 1.5826 40.41.18 23L 123 1.5899 40.7 1.19 23M 123 1.5849 40.7 1.19 23N 106 1.597741.4 1.22 23O 109 1.5956 41.2 1.23

Whereas particular embodiments of this invention have been describedabove for purposes of illustration, it will be evident to those skilledin the art that numerous variations of the details of the presentinvention may be made without departing from the invention as defined inthe appended claims.

1. A composite optical article comprising: (a) a polymeric base layercomprising a sulfur-containing urethane-based material having arefractive index of at least 1.57; and (b) a polymeric outer layer castover a surface of the base layer (a) comprising (i) apoly(urea-urethane) material having a refractive index of less than1.57, and (ii) a photochromic compound and/or a static dye, wherein thethickness of the base layer (a) is greater than the thickness of theouter layer (b).
 2. The optical article of claim 1, wherein the baselayer (a) has a thickness sufficient to maintain optical power.
 3. Theoptical article of claim 1, wherein the base layer (a) has a refractiveindex ranging from 1.57 to 1.70.
 4. The optical article of claim 1,wherein the base layer (a) comprises the reaction product of thefollowing components: (A) a reactive compound comprising a materialhaving functional groups that are reactive with active hydrogens; (B) athioether-functional, oligomeric polythiol prepared by reactingtogether: (1) a compound having at least two thiol functional groups;(2) a compound having triple bond functionality; and optionally, (3) acompound having at least two double bonds; and, optionally, (C) acompound different from (B) containing active hydrogens.
 5. The opticalarticle of claim 4, wherein the reactive compound (A) comprises adiisocyanate or a mixture of a diisocyanate and a polyisocyanate havingmore than two isocyanate functional groups.
 6. The optical article ofclaim 4, wherein the compound (1) having at least two thiol functionalgroups comprises a dithiol, a compound having more than two thiolfunctional groups, or a mixture of a dithiol and a compound having morethan two thiol functional groups.
 7. The optical article of claim 4,wherein the compound (2) having triple bond functionality comprisespropargyl alcohol, propargyl chloride, propargyl bromide, propargylacetate, propargyl propionate, propargyl benzoate, phenyl acetylene,phenyl propargyl sulfide, 1,4-dichloro-2-butyne, 2-butyne-1,4-diol,3-butyne-2-ol, 2-pentyne, 1-hexyne, 2-hexyne, 3-hexyne,3-hexyne-2,5-diol, and/or mixtures thereof.
 8. The optical article ofclaim 4, wherein the compound (3) having at least two double bonds ispresent and comprises acyclic non-conjugated dienes, acyclic polyvinylethers, allyl-(meth)acrylates vinyl-(meth)acrylates, di(meth)acrylateesters of diols, di(meth)acrylate esters of dithiols, di(meth)acrylateesters of poly(alkyleneglycol) diols, monocyclic non-aromatic dienes,polycyclic non-aromatic dienes, aromatic ring-containing dienes, diallylesters of aromatic ring dicarboxylic acids, and/or divinyl esters ofaromatic ring dicarboxylic acids.
 9. The optical article of claim 4,wherein the compound (C) is present and comprises a compound having atleast two active hydrogen-containing groups comprising primary aminegroups, secondary amine groups, hydroxyl groups, and/or thiol groups.10. The optical article of claim 1, wherein the outer layer (b) has athickness ranging from 0.5 to 1.0 millimeter.
 11. The optical article ofclaim 1, wherein the outer layer (b) has a refractive index ranging from1.50 to 1.55.
 12. The optical article of claim 1, wherein the Outerlayer (b) comprises the reaction product of: (a) a prepolymer havingisocyanate functional groups comprising the reaction product of: (i) atleast one polyol; and (ii) at least one polyisocyanate; and (b) at leastone polyamine, wherein the number of isocyanato groups of thepolyisocyanate reactants is greater than the number of hydroxyl groupsof the polyol reactants.
 13. The optical article of claim 12, whereinthe polyol (i) is selected from simple diols, ester diols, polyesterdiols, polyether diols, or mixtures thereof.
 14. The optical article ofclaim 13, wherein the polyol (i) comprises a polyester diol comprised ofpoly(caprolactone diol).
 15. The optical article of claim 12, whereinthe polyamine (b) is selected from aliphatic polyamines, alicyclicpolyamines, aromatic polyamines, ormixtures thereof.
 16. The opticalarticle of claim 1, wherein the photochromic compound (ii) is presentand comprises an organic photochromic material chosen from pyrans,oxazines, fulgides, fulgim ides, diarylethenes, or mixtures thereof. 17.The optical article of claim 1, further comprising a polarizer disposedbetween the base layer (a) and the outer layer (b).
 18. The opticalarticle of claim 1 which is a lens.
 19. The optical article of claim 18which is an ophthalmic lens.